Devices for sending and receiving feedback information

A User Equipment (UE) for sending feedback information is described. The UE includes a processor and instructions stored in memory that is in electronic communication with the processor. The UE determines a primary cell (PCell) feedback parameter corresponding to a PCell. The UE also determines a secondary cell (SCell) feedback parameter corresponding to an SCell. The SCell feedback parameter is different from the PCell feedback parameter. The UE further performs Physical Uplink Control Channel (PUCCH) Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. The UE additionally sends Hybrid Automatic Repeat Request Acknowledgement/Negative Acknowledgement (HARQ-ACK) information based on the channel selection.

TECHNICAL FIELD

The present disclosure relates generally to communication systems. More specifically, the present disclosure relates to devices for sending and receiving feedback information.

BACKGROUND

Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have become dependent upon wireless communication devices and have come to expect reliable service, expanded areas of coverage and increased functionality. A wireless communication system may provide communication for a number of wireless communication devices, each of which may be serviced by a base station. A base station may be a device that communicates with wireless communication devices.

As wireless communication devices have advanced, improvements in communication capacity, speed, flexibility and/or efficiency have been sought. However, improving communication capacity, speed, flexibility and/or efficiency may present certain problems.

For example, wireless communication devices may communicate with one or more devices using a communication structure. However, the communication structure used may only offer limited flexibility and/or efficiency. As illustrated by this discussion, systems and methods that improve communication flexibility and/or efficiency may be beneficial.

DETAILED DESCRIPTION

A UE for sending feedback information is described. The UE includes a processor and instructions stored in memory that is in electronic communication with the processor. The UE determines a PCell feedback parameter corresponding to a PCell for an uplink subframe on the PCell. The UE also determines an SCell feedback parameter corresponding to an SCell for the given uplink subframe on the PCell. The SCell feedback parameter may be the same as or different from the PCell feedback parameter in a given uplink subframe on the PCell. The UE further performs Physical Uplink Control Channel (PUCCH) Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. The UE additionally sends Hybrid Automatic Repeat Request Acknowledgement/Negative Acknowledgement (HARQ-ACK) information based on the channel selection. If the PCell feedback parameter or the SCell feedback parameter is 0 in an uplink subframe, performing PUCCH Format 1b channel selection may include performing PUCCH Format 1b channel selection according to methods or techniques and tables for one configured serving cell.

The channel selection may be performed based on a total number of associated subframes between the PCell and the SCell. The channel selection may be performed based on a maximum number of associated subframes between the PCell and the SCell. The channel selection may be performed based on a number of associated subframes of the PCell. Sending the HARQ-ACK information may include sending a first number of SCell HARQ-ACK bits that is the same as or different from a second number of PCell HARQ-ACK bits.

The channel selection may be based on at least one channel selection table. The UE may select a channel selection table based on the PCell feedback parameter and the SCell feedback parameter.

An eNB for receiving feedback information is also described. The eNB includes a processor and instructions stored in memory that is in electronic communication with the processor. The eNB determines a PCell feedback parameter corresponding to a PCell for an uplink subframe on the PCell. The eNB also determines an SCell feedback parameter corresponding to an SCell for the given uplink subframe on the PCell. The SCell feedback parameter may be the same as or different from the PCell feedback parameter. The eNB further performs PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. The eNB additionally receives HARQ-ACK information based on the channel selection. If the PCell feedback parameter or the SCell feedback parameter is 0 in an uplink subframe, performing PUCCH Format 1b channel selection may include performing PUCCH Format 1b channel selection according to methods or techniques and tables for one configured serving cell.

The channel selection may be performed based on a total number of associated subframes between the PCell and the SCell. The channel selection may be performed based on a maximum number of associated subframes between the PCell and the SCell. The channel selection may be performed based on a number of associated subframes of the PCell. Sending the HARQ-ACK information may include sending a first number of SCell HARQ-ACK bits that is the same as or different from a second number of PCell HARQ-ACK bits.

The channel selection may be based on at least one channel selection table. The eNB may select a channel selection table based on the PCell feedback parameter and the SCell feedback parameter. The eNB may send at least one of a PCell feedback parameter indicator and an SCell feedback parameter indicator.

A method for sending feedback information by a UE is also described. The method includes determining a PCell feedback parameter corresponding to a PCell. The method also includes determining an SCell feedback parameter corresponding to an SCell. The SCell feedback parameter may be the same as or different from the PCell feedback parameter. The method further includes performing PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. The method additionally includes sending HARQ-ACK information based on the channel selection.

A method for receiving feedback information by an eNB is also described. The method includes determining a PCell feedback parameter corresponding to a PCell. The method also includes determining a SCell feedback parameter corresponding to an SCell. The SCell feedback parameter may be the same as or different from the PCell feedback parameter. The method additionally includes performing PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. The method further includes receiving HARQ-ACK information based on the channel selection.

The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third and fourth generation wireless communication systems. The 3GPP may define specifications for next generation mobile networks, systems, and devices.

3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN).

At least some aspects of the systems and methods disclosed herein may be described in relation to the 3GPP LTE, LTE-Advanced (LTE-A) and other standards (e.g., 3GPP Releases 8, 9, 10 and/or 11). However, the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems.

A wireless communication device may be an electronic device used to communicate voice and/or data to a base station, which in turn may communicate with a network of devices (e.g., public switched telephone network (PSTN), the Internet, etc.). In describing systems and methods herein, a wireless communication device may alternatively be referred to as a mobile station, a UE, an access terminal, a subscriber station, a mobile terminal, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, etc. Examples of wireless communication devices include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, etc. In 3GPP specifications, a wireless communication device is typically referred to as a UE. However, as the scope of the present disclosure should not be limited to the 3GPP standards, the terms “UE” and “wireless communication device” may be used interchangeably herein to mean the more general term “wireless communication device.”

In 3GPP specifications, a base station is typically referred to as a Node B, an eNB, a home enhanced or evolved Node B (HeNB) or some other similar terminology. As the scope of the disclosure should not be limited to 3GPP standards, the terms “base station,” “Node B,” “eNB,” and “HeNB” may be used interchangeably herein to mean the more general term “base station.” Furthermore, the term “base station” may be used to denote an access point. An access point may be an electronic device that provides access to a network (e.g., Local Area Network (LAN), the Internet, etc.) for wireless communication devices. The term “communication device” may be used to denote both a wireless communication device and/or a base station.

It should be noted that as used herein, a “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (IMT-Advanced) and all of it or a subset of it may be adopted by 3GPP as licensed bands (e.g., frequency bands) to be used for communication between an eNB and a UE. “Configured cells” are those cells of which the UE is aware and is allowed by an eNB to transmit or receive information. “Configured cell(s)” may be serving cell(s). The UE may receive system information and perform the required measurements on all configured cells. “Activated cells” are those configured cells on which the UE is transmitting and receiving. That is, activated cells are those cells for which the UE monitors the physical downlink control channel (PDCCH) and in the case of a downlink transmission, those cells for which the UE decodes a PDSCH. “Deactivated cells” are those configured cells that the UE is not monitoring the transmission PDCCH. It should be noted that a “cell” may be described in terms of differing dimensions. For example, a “cell” may have temporal, spatial (e.g., geographical) and frequency characteristics.

The systems and methods disclosed herein describe devices for sending and receiving feedback information. This may be done in the context of carrier aggregation. For example, PDSCH HARQ-ACK reporting for carrier aggregation (e.g., inter-band or intra-band carrier aggregation) with different Time-Division Duplexing (TDD) UL-DL configurations is described.

In accordance with the systems and methods disclosed herein, different TDD UL-DL configurations may be used for inter-band carrier aggregation. In other words, the cells or component carriers (CCs) in different bands may have different UL-DL configurations. Carrier aggregation refers to the concurrent utilization of more than one carrier. In one example, carrier aggregation may be used to increase the effective bandwidth available to a UE. One type of carrier aggregation is inter-band carrier aggregation. In inter-band carrier aggregation, multiple carriers from multiple bands may be aggregated. For example, a carrier in a first band may be aggregated with a carrier in a second band. As used herein, the term “concurrent” and variations thereof may denote that at least two events may overlap each other in time, and may or may not mean that the at least two events begin and/or end at precisely the same time. The systems and methods disclosed herein may not be restricted to inter-band carrier aggregation and may also be applied to intra-band carrier aggregation.

As used herein, the term “configuration” may refer to an UL-DL configuration. An UL-DL configuration specifies whether each subframe within a radio frame is an UL subframe, a DL subframe or a special subframe. More detail regarding UL-DL configurations is given in connection with Table (1) below. A “PCell configuration” may refer to an UL-DL configuration that corresponds to a PCell. For example, a PCell configuration is an UL-DL configuration applied by the eNB and UE for communications in the PCell. The PCell configuration may be signaled to a UE by an eNB in a SystemInformationBlockType1 (SIB-1). The SIB-1 may be transmitted (by an eNB, for example) on a broadcast control channel as a logical channel. An “SCell configuration” may refer to an UL-DL configuration that corresponds to an SCell. For example, an SCell configuration is an UL-DL configuration applied by the eNB and UE for communications in an SCell. An SCell configuration may be signaled to a UE with carrier aggregation by an eNB in dedicated Radio Resource Control (RRC) signaling. The dedicated RRC signaling may be transmitted (by an eNB, for example) on a dedicated control channel as a logical channel.

Additionally or alternatively, an eNB may send the SCell configuration in SIB-1 for UEs using the cell as a PCell. Typically, the eNB sends the same system information parameters between the SIB-1 for UEs using the cell as the PCell and the dedicated RRC signaling for UEs with carrier aggregation, though this is not strictly required. However, the parameters that are cell-specific parameters are signaled to a UE with carrier aggregation via dedicated RRC signaling and may be signaled to UEs using the cell as a PCell may be referred to as an SCell SIB-1 configuration or an SCell configuration.

PDSCH HARQ-ACK may be reported on the uplink of the PCell. The PCell configuration, SCell configuration or a reference configuration may be used for the SCell depending on the combination of the PCell configuration and the SCell configuration. SCell PDSCH HARQ-ACK may be mapped to a PCell UL subframe allocation. An “UL subframe allocation” may refer to one or more subframes that are configured for UL transmissions. For example, a PCell UL subframe allocation may specify one or more UL subframes in accordance with the PCell configuration. A “DL subframe allocation” may refer to one or more subframes that are configured for DL transmissions. For example, a PCell DL subframe allocation may specify one or more DL subframes in accordance with the PCell configuration.

Carrier aggregation may assume that the same eNB scheduler manages communication resources for the PCell and SCell(s). Thus, the scheduler may know the actual configuration of each cell. The UEs may be informed (by an eNB, for example) of the actual UL-DL configuration of each aggregated cell, particularly if a cell has a different UL-DL configuration from the PCell.

Time-Division Duplexing (TDD) Uplink-Downlink (UL-DL) configurations may be referred to as “UL-DL configurations” or a similar term herein for convenience. Additionally, an UL-DL configuration corresponding to a PCell may be referred to as a “PCell configuration” and an UL-DL configuration corresponding to an SCell may be referred to as an “SCell configuration” for convenience herein. Furthermore, “uplink” may be abbreviated as “UL” and “downlink” may be abbreviated as “DL” for convenience herein.

Enhanced carrier aggregation (eCA) may include inter-band or intra-band carrier aggregation (CA) with different UL-DL configurations. For example, the systems and methods disclosed herein may enable inter-band CA with different UL-DL configurations, which may be supported in Rel-11. Furthermore, predetermined PDSCH HARQ-ACK reporting associations may be utilized in accordance with the systems and methods disclosed herein.

In LTE Release-8, 9 and 10 specifications, TDD CA only allows cells with the same UL-DL configuration. Therefore, the same set of parameters is utilized to determine the HARQ-ACK bits of all cells. However, for TDD CA with different UL-DL configurations, different sets of parameters may be utilized for different cells. Thus, new issues arise concerning multiplexing HARQ-ACK bits on different PUCCH formats (e.g., PUCCH Format 3 and PUCCH Format 1a/1b with channel selection).

However, a detailed PUCCH format for PDSCH HARQ-ACK reporting has not been discussed in 3GPP meetings. Reusing Release-10 specifications and adding new extensions may address these issues.

The systems and methods disclosed herein describe multiplexing and reporting HARQ-ACK information (e.g., bit(s)) for CA with different TDD configurations if a UE is configured with PUCCH Format 1b with channel selection. For example, the systems and methods disclosed herein may describe PDSCH HARQ-ACK reporting and multiplexing on PUCCH Format 1b with channel selection for carrier aggregation with different TDD UL-DL configurations. Due to different UL-DL configurations, different parameters may be used for different cells. The systems and methods disclosed herein provide approaches for determining these parameters. In particular, issues and solutions are described for the following cases.

If Format 1b with channel selection is configured on a UE, known specifications support two cells and have some limitations (e.g., the number of subframes M associated with each cell is the same and the PCell always has the same number of more PUCCH resources than the SCell). Format 1b with channel selection can support two cells, a primary cell (PCell) and a secondary cell (SCell). Due to different (TDD) UL-DL configurations, the SCell may have a different M from the PCell in a given uplink subframe. Furthermore, the M from different cells may have different values. The systems and methods disclosed herein provide improved assignment of PUCCH resources and performing channel selection for TDD CA with different UL-DL configurations.

In accordance with the systems and methods disclosed herein, the M of the PCell may be the same as provided in Rel-10 specifications. Furthermore, the systems and methods disclosed herein provide two approaches to determine the M of the SCell. In approach A, the M of the SCell is a reference parameter (e.g., MRef) based on a reference configuration. In approach B, the M of the SCell is an effective parameter (e.g., MEff) based on an effective number of subframes in the reference configuration.

Moreover, the systems and methods disclosed herein may categorize possible combinations of the M of the PCell and the M of the SCell into six cases and provide techniques to deal with these cases.

In case I, UL-DL configuration5is utilized on the PCell or an SCell or as the reference configuration of the SCell and PUCCH Format 1b with channel selection is not supported (at least in uplink subframe2, for example). It should be noted that a single-cell reporting mode for other uplinks on the PCell may be implemented in a case where the SCell configuration or SCell reference configuration is UL-DL configuration5. In case II, the MCof the PCell and the MCof the SCell are the same. In case II, Rel-10 approaches may be reused. The single-cell reporting mode means that PUCCH reporting methods or techniques for one configured serving cell, for example, PUCCH format 1a/1b or PUCCH format 1b with channel selection may be performed based on the tables defined in section 10.1.3.1 in 3GPP TS 36.213.

In case III, only the PCell has HARQ-ACK to be reported (e.g., MCof the PCell>0 and MCof the SCell=0). In case III, a single cell reporting mode may be enabled or allowed. The single cell reporting mode means that PUCCH reporting methods for one configured serving cell, for example, PUCCH format 1a/1b or PUCCH format 1b with channel selection may be performed based on the tables defined in section 10.1.3.1 in 3GPP TS 36.213. In case IV, only an SCell has HARQ-ACK to be reported (e.g., MCof the SCell>0 and the MCof the PCell=0). In case IV, a single cell reporting mode may be enabled or allowed. The introduction of single cell reporting mode for case III and case IV may provide the benefit of better PUCCH resource allocation and better HARQ-ACK channel selection mappings. If the SCell configuration or the SCell reference configuration is configuration5, single cell PUCCH channel selection reporting may be used in uplink subframes on the PCell except in subframe2.

In case V, the MCof the PCell is smaller than the MCof the SCell. In case VI, the MCof the PCell is greater than the MCof the SCell. For case V and case VI, the systems and methods disclosed herein provide four procedures (e.g., procedures1-4) to handle different M values for the PCell and SCell. In some implementations, case III may be a special case of case VI, and case IV can be a special case of case V. Therefore, the procedures disclosed here for case V and case VI can also be applied for case III and case IV as alternatives to the single cell reporting mode.

In procedure1, Mtotalis defined as the total number of subframes or total number of HARQ-ACK bits associated with the uplink. For Mtotal<5, channel selection tables with A PUCCH resources may be reused, where Aε{2, 3, 4}. Otherwise, a Rel-10 table with M=┌Mtotal/2┐ may be reused, allowing multiplexing HARQ-ACK bits from one cell to another cell. Procedure1provides the benefit of allowing an M that is a better fit (e.g., best fit) to the actual number of HARQ-ACK bits.

In procedure2, Mmaxis defined as the maximum between the MCof the PCell and the MCof the SCell. The PUCCH Format 1b with channel selection approach may then be reused for a more than one cell case in Rel-10 with M=Mmax. Procedure1may be applied as special handling of Mtotal<5 cases to reuse the channel selection tables with A PUCCH resources, where Aε{2, 3, 4}.

In procedure3, the MCof the PCell (e.g., MPCell) may be applied on the SCell, and the Rel-10 channel selection tables may be reused with M=MPCell. In this context, case V may be the same as procedure2. In case VI, where the MCof the SCell is greater than the MCof the PCell, the number of HARQ-ACK bits reported for the SCell may be truncated to the same number of HARQ-ACK bits as the PCell. Procedure2and procedure3may provide a benefit of simple solutions by reusing existing channel selection tables.

In procedure4, new channel selection tables may be defined for combinations of different MCvalues on the PCell and SCell. Procedure4may provide improved (e.g., optimized) mapping by adding new channel selection tables.

The systems and methods disclosed herein provide approaches to determine a feedback parameter (e.g., M) value (e.g., a number of subframes associated to an uplink subframe), for the PCell and SCell in case of TDD CA with different UL-DL configurations.

For TDD CA with different UL-DL configurations, PUCCH Format 1b channel selection may be performed based on the combinations of the number of subframes (e.g., PCell feedback parameter and SCell feedback parameter) associated to an uplink subframe for the PCell and SCell. If the number of associated subframes for the PCell or the SCell is 0 in an uplink subframe, single cell PUCCH Format 1b with channel selection techniques and channel selection tables may be applied.

If the number of associated subframes for the PCell and the number of associated subframes for the SCell are different, one or more options may be utilized. In a first option, channel selection may be performed based on a derived number of associated subframes (e.g., M) that is derived from the total number of associated subframes of the PCell and SCell. In some implementations, the channel selection may be performed based on the maximum number of associated subframes between the PCell and SCell. The channel selection may additionally or alternatively be performed based on the number of associated subframes of the PCell, where the SCell reports up to the same number of HARQ-ACK bits as the PCell. In some implementations, new sets of channel selection tables may be defined for combinations of different numbers of subframes for the PCell and the SCell.

eCA may support different TDD UL-DL configurations on different bands. The CA with different UL-DL configurations may also be referred to as inter-band carrier aggregation. For simplicity, an UL-DL configuration of a PCell may be referred to as a PCell configuration. Furthermore, an UL-DL configuration of an SCell may be referred to as an SCell configuration. As used herein, a “conflicting subframe” may be a subframe that has different subframe types (e.g., downlink or special subframes versus uplink subframes) between configurations.

When carrier aggregation is employed in LTE Release 10, HARQ-ACK corresponding to transmitted downlink communications may be transmitted on the PUCCH, according to one of two techniques. In one technique, HARQ-ACK may be transmitted based on Format 1b with “channel selection” or based on Format 3. Some implementations of the systems and methods disclosed herein may utilize Format 1b with channel selection, where carriers being aggregated have different UL-DL configurations.

TDD UL-DL configurations 0-6 are given below in Table (1) (from Table 4.2-2 in 3GPP TS 36.211). UL-DL configurations with both 5 millisecond (ms) and 10 ms downlink-to-uplink switch-point periodicity may be supported. In particular, seven UL-DL configurations are specified in 3GPP specifications, as shown in Table (1) below. In Table (1), “D” denotes a downlink subframe, “S” denotes a special subframe and “U” denotes an UL subframe.

The systems and methods disclosed herein may support inter-band carrier aggregation CA of TDD with different UL-DL configurations. In some implementations, PUCCH may be transmitted on the PCell only and no new HARQ-ACK timing table may be utilized beyond those already defined in Rel-8, 9 and 10 specifications. The PCell may utilize the same timing as provided in Rel-8, 9 and 10 specifications, which includes PDSCH HARQ-ACK timing, PUSCH scheduling and PUSCH HARQ-ACK timing.

The PDSCH HARQ-ACK timing issue may be categorized into three cases (cases A, B and C), depending on whether the PCell configuration is a superset of the SCell configuration, a subset of the SCell configuration or neither. In case A, where the set of DL subframes indicated by the SCell configuration is a subset of the DL subframes indicated by the PCell configuration, the SCell may follow the PCell configuration.

PDSCH HARQ-ACK reporting for the case B and case C may be implemented as follows. For the case B, at least in the context of self-scheduling and full duplex communications, where the set of DL subframes indicated by the PCell configuration is a subset of the DL subframes indicated by the SCell configuration, the SCell may follow the SCell configuration. In some implementations, the same rule may be applied in the context of half duplex communications. The systems and methods disclosed herein may present techniques for the cross-carrier scheduling case.

For the case C, at least in the context of self-scheduling and full duplex communications, where the set of DL subframes indicated by the SCell configuration is neither a subset of nor a superset of the DL subframes indicated by the PCell configuration, the SCell may follow a reference configuration as illustrated in Table (2) below. The reference configuration may be selected based on overlapping UL subframes in both the PCell and the SCell. In some implementations, the same rule may be applied in the context of half duplex communications. The systems and methods disclosed herein may present techniques for the cross-carrier scheduling case.

Table (2) below illustrates UL-DL configurations for PDSCH HARQ-ACK reporting. In particular, the columns illustrate PCell (TDD UL-DL) configurations0-6, while the rows illustrate SCell (TDD UL-DL) configurations0-6. The grid intersecting the PCell configurations and SCell configurations illustrates an UL-DL configuration with corresponding PDSCH HARQ-ACK timing that the SCell follows based on the case. In Table (2), “A” represents case A described above. In case A, SCell PDSCH HARQ-ACK timing follows the PCell configuration. In Table (2), “B” represents case B as described above. In case B, SCell PDSCH HARQ-ACK timing follows the SCell configuration. In Table (2), “C” represents case C as described above. In case C, SCell PDSCH HARQ-ACK timing follows a reference (TDD UL-DL) configuration indicated by the number that accompanies an instance of “C” in Table (2). In other words, the number in the grid in Table (2) is the reference configuration that SCell PDSCH HARQ-ACK timing follows in instances of case C. For example, when the PCell configuration is UL-DL configuration3and the SCell configuration is UL-DL configuration1, SCell PDSCH HARQ-ACK timing may follow configuration4.

In LTE Rel-10, a UE that supports aggregating more than one serving cell with frame structure type2is configured by higher layers. The UE may be configured by higher layers to use HARQ-ACK bundling, to use PUCCH Format 1b with channel selection (according to the set of Tables 10.1.3-2, 3 or 4 or according to the set of Tables 10.1.3-5, 6 or 7 of 3GPP TS 36.213, for example) or to use PUCCH Format 3 for transmission of HARQ-ACK when configured with one serving cell with frame structure type2. The use of Tables 10.1.3-2, 3 or 4 or the set of Tables 10.1.3-5, 6 or 7 of 3GPP TS 36.213 may be configured by higher layer signaling.

Known PDSCH HARQ-ACK reporting procedures on PUCCH with channel selection are described as follows. PUCCH Format 1b with channel selection is supported for TDD with a single cell or two cells. 3GPP TS 36.213 provides description of these procedures in accordance with the following. For TDD HARQ-ACK multiplexing and a subframe n with M>1, where M is the number of elements in the set K defined in Table 10.1.3.1-1 (from 3GPP TS 36.213, which is illustrated a Table (3) below), spatial HARQ-ACK bundling across multiple codewords within a DL subframe is performed by a logical AND operation of all the corresponding individual HARQ-ACKs. PUCCH Format 1b with channel selection is used in case of one configured serving cell. For TDD HARQ-ACK multiplexing and a subframe n with M=1, spatial HARQ-ACK bundling across multiple codewords within a DL subframe is not performed, 1 or 2 HARQ-ACK bits are transmitted using PUCCH format 1a or PUCCH Format 1b, respectively, for one configured serving cell.

In the case of TDD and more than one configured serving cell with PUCCH Format 1b with channel selection and more than 4 HARQ-ACK bits for M multiple DL subframes associated with a single UL subframe n, where M is the number of elements in the set K defined in Table (3) and for the configured serving cells, spatial HARQ-ACK bundling across multiple codewords within a DL subframe for all configured cells is performed and the bundled HARQ-ACK bits for each configured serving cell is transmitted using PUCCH Format 1b with channel selection. For TDD and more than one configured serving cell with PUCCH Format 1b with channel selection and up to 4 HARQ-ACK bits for M multiple DL subframes associated with a single UL subframe n, where M is the number of elements in the set K defined in Table (3) and for the configured serving cells, spatial HARQ-ACK bundling is not performed and the HARQ-ACK bits are transmitted using PUCCH Format 1b with channel selection.

Further detail regarding PUCCH Format 1b with channel selection for a single configured cell in accordance with known procedures is given as follows. For TDD HARQ-ACK bundling or TDD HARQ-ACK multiplexing for one configured serving cell and a subframe n with M=1, where M is the number of elements in the set K defined in Table (3), the UE shall use PUCCH resource nPUCCH(1,{tilde over (p)}for transmission of HARQ-PUCCH ACK in subframe n for {tilde over (p)} mapped to antenna port p for PUCCH Format 1b.

For TDD HARQ-ACK multiplexing and subframe n with M>1 and one configured serving cell, where M is the number of elements in the set K defined in Table (3), denote nPUCCH,i(1)as the PUCCH resource derived from subframe n−kiand HARQ-ACK(i) as the Acknowledgement/Negative Acknowledgement/Discontinuous Transmission (ACK/NACK/DTX) response from subframe n−ki, where kiεK (defined in Table (3)) and 0≦i≦M−1.

Based on higher layer signaling, a UE configured with a single serving cell will perform channel selection either according to the set of Tables 10.1.3-2, 10.1.3-3, and 10.1.3-4 or according to the set of Tables 10.1.3-5, 10.1.3-6, and 10.1.3-7. For the selected table set indicated by higher layer signaling, the UE shall transmit b(0), b(1) on PUCCH resource nPUCCH(1)in subframe n using PUCCH Format 1b according to section 5.4.1 in 3GPP TS 36.211. The value of b(0), b(1) and the PUCCH resource nPUCCH(1)are generated by channel selection according to the selected set of Tables for M=2, 3, and 4 respectively. PUCCH Format 1b with channel selection according to the set of Tables 10.1.3-2/3/4 or according to the set of Tables 10.1.3-5/6/7 is not supported for TDD UL-DL configuration5.

Further detail regarding PUCCH Format 1b with channel selection for two configured cells in accordance with known procedures is given as follows. A UE that supports aggregating more than one serving cell with frame structure type2is configured by higher layers to use either PUCCH Format 1b with channel selection or PUCCH format 3 for transmission of HARQ-ACK when configured with more than one serving cell with frame structure type2. TDD UL-DL configuration5with PUCCH Format 1b with channel selection for two configured serving cells is not supported.

For TDD HARQ-ACK multiplexing with PUCCH Format 1b with channel selection and two configured serving cells and a subframe n with M=1, where M is the number of elements in the set K defined in Table (3), a UE shall determine the number of HARQ-ACK bits, 0, based on the number of configured serving cells and the downlink transmission modes configured for each serving cell. The UE shall use two HARQ-ACK bits for a serving cell configured with a downlink transmission mode that supports up to two transport blocks; and one HARQ-ACK bit otherwise.

For TDD HARQ-ACK multiplexing with PUCCH Format 1b with channel selection and two configured serving cells and a subframe n with M≦2, where M is the number of elements in the set K defined in Table (3), the UE shall transmit b(0), b(1) on PUCCH resource nPUCCH(1)selected from A PUCCH resources, nPUCCH,j(1)where 0≦j≦A−1 and Aε{2, 3, 4}, according to Tables 10.1.3.2-1, 10.1.3.2-2, and 10.1.3.2-3 in subframe n using PUCCH Format 1b.

For a subframe n with M=1, HARQ-ACK(j) denotes the ACK/NACK/DTX response for a transport block or SPS release PDCCH associated with serving cell, where the transport block and serving cell for HARQ-ACK(j) and A PUCCH resources are given by Table 10.1.2.2.1-1. For a subframe n with M=2, HARQ-ACK(j) denotes the ACK/NACK/DTX response for a PDSCH transmission or SPS release PDCCH within subframe(s) given by set K on each serving cell, where the subframes on each serving cell for HARQ-ACK(j) and A PUCCH resources are given by Table 10.1.3.2-4. The UE shall determine the A PUCCH resources, nPUCCH,j(1)associated with HARQ-ACK(j) where 0≦j≦A−1 in Table 10.1.2.2.1-1 for M=1 and Table 10.1.3.2-4 for M=2.

For TDD HARQ-ACK multiplexing with PUCCH Format 1b with channel selection and subframe n with M>2 and two configured serving cells, where M is the number of elements in the set K defined in Table (3), denotes nPUCCH,i(1)0≦i≦3 as the PUCCH resource derived from the transmissions in M DL subframes associated with the UL subframe n. nPUCCH,0(1)and nPUCCH,1(1)are associated with the PDSCH transmission(s) or a PDCCH indicating downlink semi-persistent scheduling (SPS) release (defined in section 9.2 of 3GPP TS 36.213) on the primary cell and nPUCCH,2(1)and nPUCCH,3(1)are associated with the PDSCH transmission(s) on the secondary cell.

More detail is given hereafter regarding techniques for determining one or more feedback parameters (e.g., M) in CA with different UL-DL configurations (e.g., eCA) in accordance with the systems and methods disclosed herein. In LTE Rel-10 TDD CA, all cells have the same UL-DL configuration. Therefore, when determining the HARQ-ACK reporting, the same parameters are applied to all cells. In eCA, however, TDD with different configurations is supported. Thus, different cells may have different sets of parameters M. Utilizing different sets of parameters M introduces design challenges. Techniques for determining the parameter M in CA with different UL-DL configurations (e.g., eCA) are described as follows.

In LTE Rel-10, M is the number of elements in the set K defined in Table (3) below (from Table 10.1.3.1-1 of 3GPP TS 36.213) associated with subframe n and the set K. In other words, a downlink association set index for TDD may be defined in Table (3) as K:{k0, k1, . . . , kM−1}, where M is a number of elements in the set K. The downlink association set depends on the UL-DL configuration, as given in Table (3) below. It should also be noted that PDSCH HARQ-ACK timing may be based on one or more TDD UL-DL configurations in TDD CA with different configurations (as illustrated in Table (2), for example).

A PDSCH HARQ-ACK association means the linkage between a PDSCH transmission and its HARQ-ACK feedback in an uplink subframe. For an uplink subframe n, the downlink association set index for TDD is defined in Table 10.1.3.1-1, which is illustrated as Table (3) below. Thus, a PDSCH transmission in a subframe (n−k) where k belongs to the association set index K:{k0, k1, . . . , kM−1}, the corresponding HARQ-ACK of the PDSCH is reported in the associated uplink subframe n. An entry in Table (3) defines a downlink association (e.g., a PDSCH HARQ-ACK association). The set K defines the PDSCH HARQ-ACK association set for a given uplink.

In eCA, TDD with different configurations is supported. Thus, different cells may have different sets of parameters, such as M. This presents design challenges.

For self scheduling, each cell schedules the PDSCH transmission by the PDCCH or by semi-persistent scheduling (SPS) of the same cell. The PDSCH HARQ-ACK of one or more SCells is reported on the PCell according to the timing reference defined in Table (2).

For eCA with different UL-DL configurations, each cell may have different M values. MCmay be defined as the M for the cell c. In other words, MCindicates a number of subframes that require PDSCH HARQ-ACK feedback for a cell c in a given uplink subframe. It should be noted, for example, that MCmay depend on the uplink subframe. More specifically, M for a cell (e.g., MC) may be different in different uplink subframes. For the PCell, MCis the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the PCell configuration. The set K may include at least one PDSCH HARQ-ACK association k. For an SCell, the PDSCH HARQ-ACK timing may be the same or different from the SCell timing. For an SCell, since the PDSCH HARQ-ACK timing may be the same or different from the SCell timing, the PDSCH HARQ-ACK timing and the SCell timing may be determined differently in some implementations.

In approach A, the M of a SCell may be defined as MRef(e.g., the M of the reference configuration for which the PDSCH HARQ-ACK timing is followed). In other words, MRefindicates a number of subframes with a PDSCH HARQ-ACK association for a reference configuration. For case A (e.g., if the set of DL subframes indicated by the SCell configuration is a subset of the DL subframes indicated by the PCell configuration) in approach A, the SCell may follow the PCell configuration. Thus, MRef=MPCellwhere MPCellis the M of the PCell (e.g., the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the PCell configuration). In other words, MPCellindicates a number of subframes with a PDSCH HARQ-ACK association for the PCell configuration.

For case B (e.g., if the set of DL subframes indicated by the PCell configuration is a subset of the DL subframes indicated by the SCell configuration) in approach A, the SCell may follow the SCell configuration. Thus, MRef=MSCellwhere MSCellis the M of the SCell (e.g., the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the SCell configuration). In other words, MSCellindicates a number of subframes with a PDSCH HARQ-ACK association for the SCell configuration.

For case C in (e.g., if the set of DL subframes indicated by the PCell configuration is a subset of the DL subframes indicated by the SCell configuration) in approach A, the SCell may follow the reference configuration as shown in Table (2). Thus, MRef=MRefConfwhere MRefConf(e.g., a predetermined parameter) is the M of the reference configuration (e.g., the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the reference UL-DL configuration in Table (2)). In other words, MRefConfindicates a number of subframes with a PDSCH HARQ-ACK association for the reference configuration.

In case A, there are conflicting subframes, where the PCell is configured with a DL subframe (or special subframe, for example) and the SCell is configured with an UL subframe. Thus, the corresponding HARQ-ACK bits will never be generated on the SCell or they may be reported as a discontinuous transmission (DTX). For case A, m may be defined as the number of conflicting subframes, where the PCell configuration includes a DL subframe (or special subframe, for example) and SCell configurations includes an UL subframe in the set K defined in Table (3) associated with subframe n and the set K according to the PCell configuration.

Similarly in case C, there are conflicting subframes, where the reference configuration includes a DL subframe (or special subframe, for example) and the SCell configuration includes an UL subframe. Thus, the corresponding HARQ-ACK bits may never be generated on the SCell or they may be reported as a DTX. For case C, m may be defined as the number of conflicting subframes (where the PCell configuration includes a DL subframe (or special subframe, for example) and the SCell configuration includes an UL subframe) in the set K defined in Table (3) associated with subframe n and the set K according to the reference configuration in Table (2).

In approach B, the MCof an SCell may be defined as MEff, where MEffis the effective M of the reference configuration for which the PDSCH HARQ-ACK timing is followed excluding the conflicting subframes, where the PCell configuration or reference configuration includes a DL subframe (or special subframe, for example) and the SCell configuration includes an UL subframe (e.g., MEff=MRef−m). In other words, MRefis a number of subframes with PDSCH HARQ-ACK associations for the reference configuration and m is a number of the conflicting subframes that are downlink subframes and special subframes in the reference configuration and uplink subframes in the SCell configuration.

For cross-carrier scheduling, the PDSCH transmission of one cell may be scheduled from another cell with the exception that the PCell may only be scheduled by itself. Several techniques may be utilized to decide the MCof an SCell in the cross-carrier scheduling context.

In the cross-carrier scheduling context, the same techniques for self scheduling as described above may be applied. This leads to a common design for the PDSCH HARQ-ACK reporting. This may be so, for example, for implementations that support cross-carrier scheduling of a conflicting subframe (e.g., by way of cross-transmission time interval (TTI) or cross-subframe scheduling).

In known techniques, however, cross-carrier PDSCH scheduling only allows the scheduling from another cell in the same TTI. Thus, it may be simpler for an SCell to follow the HARQ-ACK timing of the scheduling cell (e.g., the PCell). Therefore, a cross-carrier scheduled cell may follow the timing of the scheduling cell.

Thus, in another approach, the MCof the SCell may follow the scheduling cell (e.g., PCell). In one implementation, the MCof the SCell may be MSchedulingCell, where MSchedulingCellis the M of the scheduling cell (where M is the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the scheduling cell UL-DL configuration). In other words, MSchedulingCellis a number of subframes with a PDSCH HARQ-ACK association for a scheduling cell configuration. In a case where the scheduling cell is not the PCell, the PDSCH reporting reference configuration of the scheduling cell may be used instead of the scheduling cell configuration. In another implementation, the MCof the SCell may be MEff—SchedulingCell, where Eff_SchedulingCell is the MEffof the scheduling cell (where MEffis the effective M of the scheduling cell configuration for which the PDSCH HARQ-ACK timing is followed, excluding the conflicting subframes, for example). In other words, MEff—SchedulingCellis a number of subframes with a PDSCH HARQ-ACK association for a scheduling cell configuration excluding conflicting subframes. In this case, a conflicting subframe may be a subframe where the scheduling cell configuration includes a DL subframe (or special subframe, for example) and the SCell configuration includes an UL subframe. In a case where the scheduling cell is not the PCell, the PDSCH reporting reference configuration of the scheduling cell may be used instead of the scheduling cell configuration.

In some implementations a feedback parameter determination scheme (to determine the MCof the SCell, for example) may be determined by or configured by the eNB. Thus, the eNB and the UE may have the same settings for the MCof the SCell.

For PDSCH HARQ-ACK reporting on PUCCH Format 1b, if MRefis configured or selected as the MCof a SCell, the same M value may be applied based on the reference configuration (e.g., the PCell configuration for case A, SCell configuration for case B, and the reference configuration in Table (2) for case C). Thus, it may be simpler to determine M for the SCell. However, it may include unnecessary bits in the report and may reduce the performance of channel selection.

For PDSCH HARQ-ACK reporting on PUCCH Format 1b, if MEffis configured or selected as the MCof a SCell, the M value may be computed based on the reference configuration to eliminate the conflicting subframes (with a DL subframe in the reference configuration and an UL subframe in the SCell configuration). Thus, the M value for the SCell may be different from the M value of the reference configuration. However, a fewer number of bits may be reported, thereby providing a potential performance gain with channel selection.

Some issues associated with CA with different TDD UL-DL configurations are described as follows. In Rel-8, 9 and 10, PUCCH Format 1b with channel selection is supported for TDD HARQ-ACK reporting in Rel-8, 9 and 10 for one configured cell, as described above (regarding PUCCH Format 1b with channel selection for a single configured cell). For M=1, spatial bundling may not be performed if there are two transport blocks in a PDSCH. For M>1, spatial bundling may be performed if there are two transport blocks in a PDSCH.

In Rel-10, channel selection is supported for carrier aggregation of two cells, and all cells have the same TDD configuration. If a UE is configured with Format 1b with channel selection, the PUCCH resources are reserved on both the PCell and the SCell. Up to two resources may be reserved for the PCell and the SCell, and the PCell may have the same number of PUCCH resources as the SCell or one more PUCCH resources than the SCell.

For M=1, spatial bundling may not be performed if there are two transport blocks in a PDSCH. For M>1, spatial bundling may be performed if there are two transport blocks in a PDSCH.

For M≦2, the number of PUCCH resources used for channel selection may be A, where Aε{2, 3, 4}. For a subframe n with M=1, HARQ-ACK(j) denotes the ACK/NACK/DTX response for a transport block or SPS release PDCCH associated with serving cell, where the transport block and serving cell for HARQ-ACK(j) and A PUCCH resources are given by Table 10.1.2.2.1-1.

For a subframe n with M=2, HARQ-ACK(j) denotes the ACK/NACK/DTX response for a PDSCH transmission or SPS release PDCCH within subframe(s) given by set K on each serving cell, where the subframes on each serving cell for HARQ-ACK(j) and A PUCCH resources are given by Table 10.1.3.2-4.

For A=2, one PUCCH Format 1b resource is associated with the PDSCH transmission(s) on the PCell and one PUCCH Format 1b resource is associated with the PDSCH transmission(s) on the SCell. Format 1b with channel selection may be performed according to Table 10.1.3.2-1.

For A=3, two PUCCH Format 1b resources are associated with the PDSCH transmission(s) on the PCell and one PUCCH Format 1b resource is associated with the PDSCH transmission(s) on the SCell. Format 1b with channel selection is performed according to Table 10.1.3.2-2.

For A=4, two PUCCH Format 1b resources are associated with the PDSCH transmission(s) on the PCell and two PUCCH Format 1b resources are associated with the PDSCH transmission(s) on the SCell. Format 1b with channel selection is performed according to Table 10.1.3.2-3.

For M>2, two PUCCH Format 1b resources are associated with the PDSCH transmission(s) on the PCell and two PUCCH Format 1b resources are associated with the PDSCH transmission(s) on the SCell. For M=3, up to 3 bits are reported on each cell. Format 1b with channel selection is performed according to Table 10.1.3.2-5. For M=4, up to 4 bits are reported on each cell. Format 1b with channel selection is performed according to Table 10.1.3.2-6. Any of these PUCCH resources are mapped on the PCell.

For TDD CA with different TDD UL-DL configurations, if PUCCH Format 1b with channel selection is configured, many issues arise due to different parameters on different cells. One of the major issues with different TDD configurations is that the M of different cells may be different in an associated UL subframe. The M of the PCell may be smaller than the M of the SCell, thus less PUCCH resources may be associated to the PCell than the SCell, and vice versa.

The difference between the M of different cells may be greater than 1, thus the PUCCH resources on the PCell and SCell may not be allocated evenly as in Rel-10. In some cases, only the PCell has a PDSCH HARQ-ACK association to an uplink, but no PDSCH-ACK is needed for the SCell (e.g., M=0 for SCell).

If the PCell configuration is UL-DL configuration0, in subframe3and subframe8, there is no HARQ-ACK to be reported on PCell (e.g., M=0 for the PCell). Thus, only HARQ-ACK bits from the SCell may be reported.

Therefore, in some cases, the Rel-10 resource allocation techniques and channel selection mappings tables may not be used directly for TDD CA with different TDD configurations. Special handling may be needed.

The systems and methods disclosed herein present solutions to the aforementioned issues. As an extension to Rel-10, for TDD CA with different TDD UL-DL configurations, Format 1b with channel selection may be used for two configured cells. Furthermore, Format 1b with channel selection may not be supported if configuration5is configured on either the PCell or the SCell, or if configuration5is used as the reference configuration for the SCell.

The MCof the PCell (e.g., MPCell) may be the same as in Rel-10 (e.g., the MPCellis the number of elements in the set K defined in Table (3) associated with subframe n and the set K according to the PCell configuration).

In approach A, the MCof the SCell may be selected as MRef. Thus, the MCof an SCell may be MPCellin case A, MSCellM in case B, and MRefConfin case C in accordance with Table (2).

Table (4) below lists the combinations of the MCof the PCell and the MCof the SCell as MRef. The PUCCH Format 1b reports in an uplink may be classified into five cases as follows. In case I, TDD UL-DL Configuration5is used on PCell or SCell or as the reference configuration of SCell. In case II, the MCof the PCell and the MCof the SCell are the same. In case III, only the PCell has HARQ-ACK to be reported (e.g., the MCof the PCell>0 and the MCof the SCell=0). In case IV, only the SCell has HARQ-ACK to be reported (e.g., the MCof the SCell>0 and the MCof the PCell=0). In case V, the MCof the SCell is smaller than the MCof the SCell.

In approach B, the M of the SCell may be selected as MEff(e.g., the effective M of the reference configuration for the SCell excluding the conflicting subframes (where the reference configuration is configured with a DL subframe (or special subframe) and the SCell is configured with an UL subframe. The reference configuration is defined in Table (2) (e.g., the reference configuration is the PCell configuration in case A, the SCell configuration in case B, and the reference configuration indicated in Table (2) in case C).

In approach B, Table (5) below lists the combinations of the MCof the PCell and the M of the SCell as MEff. Approach B eliminates the HARQ-ACK bits for conflicting subframes (where the reference configuration is configured with a DL subframe (or special subframe) and the SCell is configured with an UL subframe). Thus, it is beneficial to reduce the required HARQ-ACK bits for PUCCH reporting, and may potentially enhance the HARQ-ACK report performance. The PUCCH Format 1b reports may be classified into six cases. Compared with approach A, there is another case VI, where the MCof the PCell is greater than the MCof the SCell. In case VI, the MCof the PCell is greater than the MCof the SCell. In some implementations, all cases in approach A may be included in approach B and case VI.

Tables (4A) and (4B) below illustrate combinations of the MCof the PCell and the MCof the SCell as MRef. Tables (4A) and (4B) may be collectively referred to as Table (4). In Tables (4) and (5), roman numerals (e.g., I-VI) may denote cases I-VI, respectively.

Tables (5A) and (5B) below illustrate combinations of the MCof the PCell and the MCof the SCell as MEff. Tables (5A) and (5B) may be collectively referred to as Table (5).

Procedures for each of the cases listed above are described as follows. In case I, if TDD UL-DL configuration5is the reference configuration of the SCell, PUCCH Format 1b with channel selection is not supported. Case I may include when TDD UL-DL configuration5is configured on the PCell or the SCell and when TDD UL-DL configuration5is the reference configuration in case C in Table (2). This may be an extension of Rel-10. In some implementations, if the SCell configuration or the SCell reference configuration is configuration5, single cell PUCCH channel selection reporting may be used in uplink subframes on the PCell, except in subframe2, which is the same as in case III below. Therefore, in Table (4) and Table (5), case III is included in brackets besides case I in this scenario. If the SCell configuration or the SCell reference configuration is configuration5and only two cells are configured for carrier aggregation, the single-cell PUCCH Format 1b with channel selection technique may be used in uplink subframes, except subframe2, because the PDSCH may only be detected on the PCell.

In case II, if the MCof the PCell and the MCof the SCell are the same in an uplink subframe, the PUCCH Format 1b with channel selection techniques of Rel-10 may be reused. It should be noted that for case II, the SCell reference configuration may or may not be the same as the PCell TDD UL-DL configuration. Especially, with approach A, all uplink subframes will correspond to case II if the SCell reference configuration is the same as PCell UL-DL configuration. For instance, with approach B, the M of the SCell may be different because SCell UL may be removed from the association set.

With approach A, in some PCell and SCell combinations, there may be conflicting subframes where the reference configuration is configured with a DL subframe (or special subframe) and the SCell configuration is configured with an UL subframe. Thus, the corresponding HARQ-ACK bits may never be generated on the SCell, or they may always be reported as DTX.

In case III, only the PCell needs to report HARQ-ACK information in an uplink (e.g., the MCof the PCell is greater than 0, and the MCof the SCell is 0 or there is no PDSCH HARQ-ACK association for the SCell in the given uplink). The possible values MCof the PCell are MPCell=1 or MPCell=2 in case III as illustrated in Table (4) and Table (5). It should be noted that with approach B, uplink reporting may correspond to case III even if the PCell configuration is used as the reference configuration for the SCell (e.g., in subframe3and subframe8when the PCell is configured with TDD UL-DL configuration1and the SCell is configured with TDD UL-DL configuration0). For instance, by removing the ULs in the SCell association set, the M of SCell may be different from the M of the PCell.

In Rel-10, both the PCell and the SCell have the same M value. Therefore, case III is not supported in current Rel-10 specifications. There are two procedures (denoted procedure III.1 and III.2 for convenience) to solve this issue in accordance with the systems and methods disclosed herein.

In procedure III.1, a single cell reporting procedure is applied for case III UL reports in TDD CA with different TDD UL-DL configurations. In Rel-10, since the M of both the PCell and the SCell are the same, Format 1b with channel selection is used even if no PDSCH is detected on the SCell. Thus, channel selection is always performed based on two configured cells. Up to two PUCCH resources can be allocated for both the PCell and the SCell. With procedure1, no PUCCH resource needs to be allocated for the SCell, and all PUCCH resources may be dynamically allocated or configured by higher layer signaling for the PCell. Resource allocation and mapping tables may follow the one configured serving cell case in Section 10.1.3.1 of 3GPP TS 36.213. For case III UL reports in TDD CA with different TDD UL-DL configurations and MPCell=1, PUCCH format 1a/1b is used on a single PUCCH resource and no channel selection is needed. For case III, UL reports in TDD CA with different TDD UL-DL configurations and MPCell=2 based on higher layer signaling, a UE may be configured with channel selection either according to the set of Tables 10.1.3-2 or according to the set of Tables 10.1.3-5.

The benefits of procedure III.1 are the reduced number of PUCCH resources allocated and more accurate HARQ-ACK mapping in the channel selection tables. No PUCCH resources are needed for the SCell. Only one PUCCH Format 1a/1b resource is allocated for the PCell for MPCell=1. The UE may allocate two PUCCH Format 1b resources for MPCell=2. Spatial HARQ-ACK bundling across multiple codewords within a DL subframe may be performed based on a logical AND operation of all the corresponding individual HARQ-ACKs if a PDSCH has two codewords.

In procedure III.2, if the MCof the SCell is set with MPCell(e.g., the MCof the PCell), then PUCCH Format 1b with channel selection procedure may be reused for the more than one cell case in Rel-10 with M=MPCell. With procedure III.2, the HARQ-ACK bits corresponding to the SCell may be reported as DTX. The benefit of procedure2is to reuse the channel selection tables for more than one configured serving cell (e.g., the sets of channel selection tables for a single configured cell are not used for TDD CA). For M=1, if the PDSCH on the PCell has one codeword, Table 10.1.3.2-1 for A=2 may be used. For M=1, if the PDSCH on the PCell has two codewords, Table 10.1.3.2-2 for A=3 or Table 10.1.3.2-3 for A=4 may be used. For M=2, Table 10.1.3.2-3 for A=4 may be used.

The disadvantages of procedure III.2 are the waste of resource assignment on the SCell and the poor HARQ-ACK bit mapping in the sets of channel selection tables. Even if PUCCH channel resources are configured for the SCell following the rules in 10.1.3.2 in 3GPP TS 36.213, they may not be used to carry the PUCCH feedback due to the mapping table design characteristics. Furthermore, since all SCell HARQ-ACK bits are set with DTX, the actual HARQ-ACK bits of the channel selection are reduced.

In case IV, only the SCell needs to report HARQ-ACK information in an uplink, (e.g., the MCof the SCell is greater than 0, and the MCof the PCell is 0 or there is no PDSCH HARQ-ACK association for the PCell in the given uplink). Case IV only happens in subframe3and subframe8when the PCell is configured with TDD UL-DL configuration0. In case IV, the possible MCof the SCell may be 1, 2, and 4 as shown in Table (4) and Table (5).

In Rel-10, both the PCell and the SCell have the same M value. Therefore, case IV is not supported in current Rel-10 specifications. Similar to case III, there are two procedures (denoted procedure IV.1 and IV.2 for convenience) to solve this issue in accordance with the systems and methods disclosed herein.

In procedure IV.1, a single cell reporting procedure is applied for case IV UL reports in TDD CA with different TDD UL-DL configurations. In Rel-10, since the M of both the PCell and the SCell are the same, Format 1b with channel selection is used even if no PDSCH is detected on the PCell. Thus, channel selection is always performed based on two configured cells. Up to two PUCCH resources can be allocated for both the PCell and the SCell. With procedure IV.1, no PUCCH resource needs to be assigned for the PCell. Furthermore, more than two PUCCH resources may be needed on the SCell (e.g., four PUCCH resources may be needed to support M=4 on the SCell). With procedure IV.1, the PUCCH resources for the SCell may be dynamically allocated or configured by higher layer signaling.

For a PDSCH transmission indicated by the detection of a corresponding PDCCH on the secondary cell within the subframe(s) n−k, where kεK of the reference configuration of the SCell determined based on Table (2), (e.g., PDSCH is self scheduled on the SCell), no dynamic or implicit PUCCH assignment is possible and all PUCCH resources may be configured by higher layer signaling.

For a PDSCH transmission indicated by the detection of a corresponding PDCCH on the primary cell within the subframe(s) nk, where k E K of the reference configuration of the secondary cell is determined based on Table (2), (e.g., the PDSCH on the SCell is cross-carrier scheduled by the PCell), the PUCCH resource can be dynamically and implicitly allocated. For example, the PUCCH resource nPUCCH,i(1)=(M−i−1)·NC+i·NC+1+nCCE,i+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that NC≦nCCE,i<NC+1, NC=max{0, └[NRBDL·(NscRB·C−4)]/36┘}, where nCcE,iis the number of the first Control Channel Element (CCE) used for transmission of the corresponding PDCCH in subframe n−kiand NPUCCH(1)is configured by higher layers.

With procedure IV.1, the channel selection mapping tables may follow the one configured serving cell case in Section 10.1.3.1 of 3GPP TS 36.213. For case IV UL reports in TDD CA with different TDD UL-DL configurations and when the MCof the SCell is 1, only one PUCCH Format 1a/1b resource may be used, and no channel selection is performed. Format 1a may be used if there is only one codeword in the PDSCH transmission. Format 1b may be used if there are two codewords blocks in the PDSCH transmission.

For case IV UL reports in TDD CA with different TDD UL-DL configurations and when the MCof the SCell greater than 1, based on higher layer signaling, a UE may be configured with channel selection either according to the set of Tables 10.1.3-2, 10.1.3-3, and 10.1.3-4 or according to the set of Tables 10.1.3-5, 10.1.3-6, and 10.1.3-7.

The benefits of procedure IV.1 are the reduced number of PUCCH resources allocated and more accurate HARQ-ACK mapping in the channel selection tables. No PUCCH resources are needed for the PCell. One PUCCH format 1a/1b resource may be allocated for the SCell for Mscen=1 with one or two codewords. Two PUCCH Format 1b resources may be allocated if the MCof the SCell is 2. Four PUCCH Format 1b resources may be allocated if the MCof the SCell is 4. If the MCof the SCell is greater than 1, and a PDSCH is configured with two codewords, the HARQ-ACK bits of the two codewords may be spatially bundled to one HARQ-ACK bit.

In procedure IV.2, if the MCof the PCell is set with the MCof the SCell, then the PUCCH Format 1b with channel selection procedure may be reused for the more than one cell case in Rel-10 with M=MCof the SCell. With procedure IV.2, the HARQ-ACK bits corresponding to the PCell may be reported with DTX. The advantage of procedure IV.2 is to reuse the channel selection tables for more than one configured serving cell (e.g., the sets of channel selection tables for a single configured cell are not used for TDD CA). For M=1, if the PDSCH on the SCell has one codeword, Table 10.1.3.2-1 for A=2 may be used. For M=1 and PDSCH on SCell has two codewords or M=2, Table 10.1.3.2-3 for A=4 may be used. For M=4, Table 10.1.3.2-6 may be used.

The disadvantages of procedure IV.2 are the waste of resource assignment on the PCell and the poor HARQ-ACK bit mapping in the sets of channel selection tables. Even if PUCCH channel resources are configured for the PCell following the rules in Section 10.1.3.2 in 3GPP TS 36.213, they may not be used to carry the PUCCH feedback due to the mapping table design characteristics. Furthermore, since all PCell HARQ-ACK bits are set with DTX, the actual codeword space of the channel selection tables are greatly reduced. Thus, the HARQ-ACK of the SCell are not reported as accurately as that of a single cell case, especially for the M=4 case.

In case V, the MCof the PCell is smaller than the MCof the SCell. In Rel-10, both the PCell and the SCell have the same M value. Therefore, case V is not supported in current Rel-10 specifications.

With approach A as shown in Table (4), the combinations of MCof the PCell and the SCell in case V include: MCof the PCell=1, MCof the SCell=2; MCof the PCell=1, MCof the SCell=3; MCof the PCell=1, MCof the SCell=4; MCof the PCell=2, MCof the SCell=4; and MCof the PCell=3, MCof the SCell=4. With approach B as shown in Table (5), in addition to all the combinations of approach A, there is another combination with MCof the PCell=2, MCof the SCell=3. The MCof the PCell is 0 in case IV. Therefore, case IV may be a special instance of case V and may follow the same approaches as case V alternatively from the approaches described for case IV above.

In case VI, the MCof the PCell is greater than the MCof the SCell. In Rel-10, both the PCell and the SCell have the same M value. Therefore, case VI is not supported in current Rel-10 specifications.

Case VI may happen in an uplink report only in approach B when the effective value MEffis used as MCof the SCell. More specifically, case VI uplink reporting will happen in some uplink subframes for case A and case C in Table (2) where the SCell reference configuration is different from the TDD UL-DL configuration of the SCell. With approach B as shown in Table (5), the combinations of MCof the PCell and the SCell in case VI include: MCof the PCell=2, MCof the SCell=1; MCof the PCell=4, MCof the SCell=1; MCof the PCell=4, MCof the SCell=2; and MCof the PCell=4, MCof the SCell=3. The MCof the SCell is 0 in case III. Therefore, case III may be a special instance of case V and may follow the same approaches as case V alternatively from the approaches described for case III above.

For both case V and case VI, there are several procedures to solve these issues. In procedure V.1 or VI.1, Mtotalmay be defined as the total number of subframes or total number of HARQ-ACK bits associated with the uplink. In way A, Mtotalis the total number of subframes associated to the given uplink for all cells. Therefore, Mtotalis the sum of MCof the PCell and the MCof the SCell (e.g., Mtotal=MPcell+MCof the SCell, where the MCof the SCell is MRefwith approach A or MEffwith approach B). In way B, in case MCof one cells is 1, Mtotalmay be defined as the total number of HARQ-ACK bits associated with a given uplink. Thus, Mtotal=max(MCof the PCell and the Scell)+1 if a transmission mode that supports only one transport block is configured on the serving cell with MC=1, where max(MCof the PCell and the Scell) returns the maximum MCvalue between the MCof the PCell and the MCof the SCell; Mtotal=max(MCof the PCell and the Scell)+2 if a transmission mode that supports two transport blocks is configured on the serving cell with MC=1.

Then, M=┌Mtotal/2┐ may be derived and existing Rel-10 mapping tables may be reused based on Mtotaland the derived M (e.g., M derived) For example, if Mtotal=5, reuse existing mapping table with derived M=3. If Mtotal=7, reuse mapping table with derived M=4. If Mtotalis smaller than or equal to 4, PUCCH Format 1b with channel selection may be performed according to the channel selection Tables 10.1.3.2-1/2/3 with A=Mtotaland Aε{2,3,4}.

If Mtotalis greater than 4, due to different MCvalues of the PCell and SCell, one HARQ-ACK bit of the cell with higher MCmay need to be truncated to derived M=┌Mtotal/2┐ bits and the truncated bit may be multiplexed to the HARQ-ACK bits of the cell with smaller MC. If necessary, a DTX is padded to the end of the cell with smaller MCto let the total number of bits reach to derived M=┌Mtotal/2┐.

The benefit of this procedure V.1 or VI.1 is to provide the best matching M to the actual HARQ-ACK payload. The minimum M value is used to determine the channel selection mapping table. The potentially smaller M may lead to better HARQ-ACK accuracy for a PUCCH report.

The main disadvantage of procedure V.1 or VI.1 is extra complexity for the HARQ-ACK bit multiplexing of different cells. Another issue with procedure V.1 or VI.1 is the error propagation to the truncated bit of the cell with higher MCfrom the HARQ-ACK bits of the cell with higher MC. If a HARQ-ACK bit in the cell with lower MCis a DTX, the truncated bit of the cell with higher MCmay be considered “any” in the channel selection table (e.g., the bit may not be considered in the decoding). However, the truncated bit may only carry HARQ-ACK information when DAI of the PDCCH on the cell with higher MCis the same as the higher MCvalue (e.g., all DL subframes are scheduled with PDSCH transmission to a given UE). The chance is very low, and the benefit of enhanced HARQ-ACK accuracy with reduced M can be justified and compensated for by the very low probability of all DL subframes that are scheduled with PDSCH transmissions to the given UE in the cell with higher MC.

For the tables below, in Tables with A=3 and A=4, the nth subframe of a serving cell is the nth subframe in the association set of the serving cell in time ordering. For a cell with MC=1 and MC=2, HARQ-ACK(j) of the cell is the HARQ-ACK response of the (j+1)th subframe in the association set with time ordering.

For the tables below, for the PCell and MC>2, if there is a PDSCH transmission on the primary cell without a corresponding PDCCH detected within the subframe(s) n−k, where kεK, HARQ-ACK(0) is the ACK/NACK/DTX response for the PDSCH transmission without a corresponding PDCCH. HARQ-ACK(j), where 1≦j≦MC−1, is the ACK/NACK/DTX response for the PDSCH transmission with a corresponding PDCCH and DAI value in the PDCCH equal to ‘j’, or for the PDCCH indicating downlink SPS release and with a DAI value in the PDCCH equal to ‘j’. Otherwise, HARQ-ACK(j), where 1≦j≦MC−1, is the ACK/NACK/DTX response for the PDSCH transmission with corresponding PDCCH and a DAI value in the PDCCH equal to ‘j+1’ or for the PDCCH indicating downlink SPS release and with DAI value in the PDCCH equal to ‘j+1’. For the tables below, for the SCell and MC>2, the HARQ-ACK(j) of the serving cell, where 1≦j≦MC−1, is the ACK/NACK/DTX response for the PDSCH transmission with a corresponding PDCCH and a DAI value in the PDCCH equal to ‘j+1’.

In Rel-10, all cells have the same M. If M=1, no HARQ-ACK spatial bundling is performed. Thus 1 or 2 bits of HARQ-ACK are reported in a subframe for PDSCH with one or two codewords, respectively. If M>1, HARQ-ACK spatial bundling may be always performed, and thus only 1 bit of HARQ-ACK is reported in a subframe for PDSCH with either one or two codewords.

For case V uplink reporting, in way V.1.A, Mtotalis defined as the total number of subframes and spatial bundling is performed according to the derived M=┌Mtotal/2┐. Since the derived M is always greater than 1, spatial bundling is always performed. Table (6), Table (7), Tables (8A) and (8B) (referred to collectively as Table (8)) and Tables (9A) and (9B) (referred to collectively as Table 9) list the possible combinations for case V with way V.1.A, which may be applicable to both approach A and approach B.

For case V uplink reporting, in way V.1.B, if one cell with MC=1, and Mtotalis set as the total number of HARQ-ACK bits that are associated with a given uplink subframe, and the derived M=┌Mtotal/2┐ no HARQ-ACK spatial bundling may be performed for the cell with MC=1. The possible combinations in case V with MC=1 for PCell with way V.1.B are listed in Table (10), Tables (11A) and (11B) (collectively referred to as Table (11)) and Tables (13A) and (13B) (collectively referred to as Table (13)). Tables (12A) and (12B) (collectively referred to as Table (12)) provides an alternative mapping to Table (11) for the MCof PCell=1 for PUSCH with one codeword, and the MCof SCell=3. With A=4, the 4-bit HARQ-ACK from the SCell may be in regular order other than the truncation from the cell with higher MC, then multiplexed on the cell with lower MC.

In case V, the MCof the SCell is always greater than 1 and the PUCCH resources associated with the SCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213. If the MCof the PCell is greater than 1, the PUCCH resources associated with the PCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213. If the MCof the PCell is 1, the PUCCH resources associated with the PCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213, assuming a transmission mode that supports up to two transport blocks on the serving cell.

For case VI uplink reporting, in way VI.1.A, Mtotalis defined as the total number of subframes and spatial bundling is performed according to the derived M=┌Mtotal/2┐. Since the derived M is always greater than 1 in this case, spatial bundling is always performed. Table (14), Tables (15A) and (15B) (collectively referred to as Table (15)) and Tables (16A) and (16B) (collectively referred to as Table (16)) list the possible combinations for case VI with way VI.1.A, which is only applicable to approach B.

For case VI uplink reporting, in way VI.1.B, if one cell with MC=1, and Mtotalis defined as the total number of HARQ-ACK bits, and M=┌Mtotal/2┐, no HARQ-ACK spatial bundling may be performed for the cell with MC=1. The possible combinations in case VI with way VI.1.B are listed in Table (17), Table (18) and Tables (19A) and (19B) (collectively referred to as Table (19)).

In case VI, the MCof the PCell is always greater than 1 and the PUCCH resources associated with the PCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213. If the MCof the SCell is greater than 1, the PUCCH resources associated with the PCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213. If the MCof the SCell is 1, the PUCCH resources associated with the PCell may be allocated in the same way as in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213, assuming a transmission mode that supports up to two transport blocks on the serving cell. The PUCCH resources associated with the SCell are configured by higher layer (signalling, for example) if the PDSCH transmission is self-scheduled on the SCell. The PUCCH resources associated with the SCell may be dynamically allocated if the PDSCH transmission is cross-carrier scheduled by the PDCCH of the PCell, as described in in Rel-10 Section 10.1.3.2.1 in 3GPP TS 36.213.

In procedure V.2 or VI.2, Mmaxmay be defined as the maximum between the MCof the PCell and the MCof the SCell. In procedure V.2 or VI.2, the PUCCH Format 1b with channel selection technique may be reused for the more than one cell case in Rel-10 with M=Mmax. With procedure V.2 or VI.2, the extra HARQ-ACK bits of the configured cell with smaller MCmay be padded with DTX to a total of Mmaxbits. The sets of Tables 10.1.3.2-4/5/6 may be used for Mmax=2, Mmax=3 and Mmax=4, respectively, as shown in Table (20), Tables (21A) and (21B) (collectively referred to as Table (21) and Tables (22A) and (22B) (collectively referred to as Table (22)), respectively. For Mmax=2, Table (23) uses the channel selection Table 10.1.3.2-4 for A=4.

One benefit of procedure V.2 or VI.2 is simplicity. It provides a simple technique to reuse the channel selection tables for more than one configured serving cells. However, it has several disadvantages too. First, for TDD HARQ-ACK multiplexing and a subframe n with M>1, where M is the number of elements in the set K defined in Table (3) and spatial HARQ-ACK bundling across multiple codewords within a DL subframe is performed by a logical AND operation of all the corresponding individual HARQ-ACKs. Because Mmaxis always greater than 1 in this case, HARQ-ACK spatial bundling is always performed if two codewords are transmitted on PDSCH, even if the MCof the PCell in case V or the MCof the SCell in case VI is 1. Therefore, HARQ-ACK spatial bundling may follow the MCof the cell itself. Therefore, two HARQ-ACK bits may be reported if two codewords are transmitted on the PDSCH for the cell with MC=1. Table (23), Tables (24A) and (24B) (collectively referred to as Table (24)) and Tables (25A) and (25B) (collectively referred to as Table (25) show the mappings for one of the cell with MC=1 and Mmax=2, Mmax=3, Mmax=4, respectively. For Mmax=2, Table 21 uses the channel selection Table 10.1.3.2-4 for A=4.

Secondly, since extra HARQ-ACK bits are padded with DTX, the actual codeword spaces of the channel selection tables are greatly reduced. For the same number of actual information carrying HARQ-ACK bits, a PUCCH Format 1b with channel selection with a higher M value is normally worse than a PUCCH Format 1b with channel selection with a lower M value.

Therefore, there can be several special handlings for Mtotal<5, thus the tables in Rel-10 with A=3, 4 can also be reused. The same sets of mapping tables as in procedure V.1 or VI.1 above may be reused as special handling cases in procedure V.2 or VI.2 with and without spatial bundling for the cell with MC=1.

In the following description, A=3. For A=3, Table (6), Table (10), Table (14), and Table (17) in procedure V.1 or VI.1 may be applied: MCof the SCell is 2, MCof the PCell is 1 and PDSCH transmission with one codeword or two codewords with spatial bundling; MCof the PCell is 2, MCof the SCell is 1 and PDSCH transmission with one codeword or two codewords with spatial bundling.

In the following description, A=4. For A=4, Table (7), Table (12) (or Table (11)) and Table (18) in procedure V.1 or VI.1 may be applied: MCof the SCell is 2, MCof the PCell is 1 and PDSCH transmission with two codewords and no spatial bundling; M of the PCell is 2, M of the SCell is 1 and PDSCH transmission with two codewords and no spatial bundling; MCof the SCell is 3, MCof the PCell is 1 and PDSCH transmission with one codeword or two codewords with spatial bundling.

In procedure V.3 or VI.3, the MCof the PCell (e.g., MPCell) may be applied to the SCell, and the Rel-10 channel selection tables may be reused with M=MPCellFor case VI, where the MCof the PCell is greater than the MCof the SCell, procedure VI.3 is the same as procedure VI.2.

For case V, where the MCof the PCell is smaller than the MCof the SCell, HARQ-ACK bundling may be performed on the SCell to generate the same number of HARQ-ACK bits as the PCell. This technique has better backward compatibility in terms of PUCCH resource allocation and mapping tables. However, the HARQ-ACK bundling of SCell bits leads to worse HARQ-ACK reporting results. Especially, in this case, if cross subframe or cross TTI bundling is applied, ACK feedback is possible only if all DL subframes in the SCell are scheduled with PDSCH transmission.

A more subtle technique is to report the same number of HARQ-ACK bits of the SCell as the PCell. If the MCof the PCell is 1 with a transmission mode that supports one codeword on the PCell, one HARQ-ACK bit is reported for the first subframe on the SCell (e.g., the subframe for a PDSCH transmission on the SCell with a corresponding PDCCH in subframe n−km, where kmεK of the reference configuration of the SCell) with the DAI value in the PDCCH equal to ‘1’. DTX may be reported if the corresponding DAI is not received. Channel selection is performed on Table 10.1.3.2-1: transmission of HARQ-ACK multiplexing for A=2, as shown in Table (26). The HARQ-ACK is not reported for PDSCH transmissions of a corresponding PDCCH with DAI values greater than 1. Thus, the eNB may attempt to avoid scheduling such PDSCH transmissions.

If the MCof the PCell is 1 with a transmission mode that supports two codewords on the PCell, two HARQ-ACK bits are reported for the SCell for the first subframe and the second subframe on the SCell (e.g., PDSCH transmissions on the SCell with corresponding PDCCH in subframe n−km, where kmεK of the reference configuration of the SCell) with the DAI value in the PDCCH equal to either ‘1’ or ‘2’. DTX is reported if the corresponding DAI is not received. Channel selection is performed on Table 10.1.3.2-3: transmission of HARQ-ACK multiplexing for A=4, as shown in Table (27). The HARQ-ACK is not reported for PDSCH transmissions of a corresponding PDCCH with DAI values greater than 2. Thus, the eNB may attempt to avoid scheduling such PDSCH transmissions.

If the MCof the PCell is 2, up to two HARQ-ACK bits are reported for the SCell for the first subframe and the second subframe on the SCell (e.g., PDSCH transmissions on the SCell with corresponding PDCCH in subframe n−km, where kmεK of the reference configuration of the SCell) with the DAI value in the PDCCH equal to either ‘1’ or ‘2’. DTX is reported if the corresponding DAI is not received. Channel selection is performed on Table 10.1.3.2-3: transmission of HARQ-ACK multiplexing for A=4, as shown in Table (28). The HARQ-ACK is not reported for PDSCH transmissions of a corresponding PDCCH with DAI values greater than 2. Thus, the eNB may attempt to avoid scheduling such PDSCH transmissions.

If the MCof the PCell is 3, up to three HARQ-ACK bits are reported for the SCell for the first subframe, the second subframe and the third subframe on the SCell (e.g., PDSCH transmissions on the SCell with corresponding PDCCH in subframe n−km, where kmεK of the reference configuration of the SCell) with the DAI value in the PDCCH equal to either ‘1’, or ‘2’ or ‘3’ respectively, as shown in Tables (29A) and (29B) (collectively referred to as Table (29). DTX is reported if the corresponding DAI is not received. The HARQ-ACK is not reported for PDSCH transmissions of a corresponding PDCCH with DAI values greater than 3. Thus, the eNB may attempt to avoid scheduling such PDSCH transmissions.

In procedure V.4 and VI.4, new channel selection mapping tables can be defined for the case V and case VI, where the MCof the PCell is different from the MCof the SCell. The sets of mapping tables may be derived from existing mapping tables for M=3 and M=4 by padding DTX to the cells with smaller MC, similar to procedure V.2 or VI.2 above. The tables may also be designed to better match the combinations of the MCof the PCell and the MCof the SCell.

For reference, additional Tables from 3GPP specifications are provided as follows. It should be noted that “Transport Block” is abbreviated as “TB” in the Tables for convenience herein.

Various examples of the systems and methods disclosed herein are now described with reference to the Figures, where like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different implementations. Thus, the following more detailed description of several implementations, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods.

FIG. 1is a block diagram illustrating one configuration of one or more eNBs160and one or more UEs102in which systems and methods for sending and receiving feedback information may be implemented. The one or more UEs102communicate with one or more eNBs160using one or more antennas122a-n. For example, a UE102transmits electromagnetic signals to the eNB160and receives electromagnetic signals from the eNB160using the one or more antennas122a-n. The eNB160communicates with the UE102using one or more antennas180a-n.

The UE102and the eNB160may use one or more channels119,121to communicate with each other. For example, a UE102may transmit information or data to the eNB160using one or more uplink channels121. Examples of uplink channels121include a PUCCH and a PUSCH, etc. The one or more eNBs160may also transmit information or data to the one or more UEs102using one or more downlink channels119, for instance. Examples of downlink channels119include a PDCCH, a PDSCH, etc. Other kinds of channels may be used.

Each of the one or more UEs102may include one or more transceivers118, one or more demodulators114, one or more decoders108, one or more encoders150, one or more modulators154, a data buffer104and a UE operations module124. For example, one or more reception and/or transmission paths may be implemented in the UE102. For convenience, only a single transceiver118, decoder108, demodulator114, encoder150and modulator154are illustrated in the UE102, though multiple parallel elements (e.g., transceivers118, decoders108, demodulators114, encoders150and modulators154) may be implemented.

The transceiver118may include one or more receivers120and one or more transmitters158. The one or more receivers120may receive signals from the eNB160using one or more antennas122a-n. For example, the receiver120may receive and downconvert signals to produce one or more received signals116. The one or more received signals116may be provided to a demodulator114. The one or more transmitters158may transmit signals to the eNB160using one or more antennas122a-n. For example, the one or more transmitters158may upconvert and transmit one or more modulated signals156.

The demodulator114may demodulate the one or more received signals116to produce one or more demodulated signals112. The one or more demodulated signals112may be provided to the decoder108. The UE102may use the decoder108to decode signals. The decoder108may produce one or more decoded signals106,110. For example, a first UE-decoded signal106may comprise received payload data, which may be stored in a data buffer104. A second UE-decoded signal110may comprise overhead data and/or control data. For example, the second UE-decoded signal110may provide data that may be used by the UE operations module124to perform one or more operations.

As used herein, the term “module” may mean that a particular element or component may be implemented in hardware, software or a combination of hardware and software. However, it should be noted that any element denoted as a “module” herein may alternatively be implemented in hardware. For example, the UE operations module124may be implemented in hardware, software or a combination of both.

In general, the UE operations module124may enable the UE102to communicate with the one or more eNBs160. The UE operations module124may include one or more of UL-DL configurations128, a UE UL-DL configuration determination module130, a HARQ-ACK generation module132, a UE reporting subframe determination module134, a UE feedback parameter determination module126and a format application module184.

The UL-DL configurations128may specify a set of UL-DL configurations that may be used for communication between the UE102and the eNB160. Examples of UL-DL configurations include the UL-DL configurations0-6illustrated in Table (1) above. The UL-DL configurations128may specify UL, DL and special subframes for communication with the eNB(s)160. For example, the UL-DL configurations128may indicate DL subframes for the UE102to receive information from the eNB160and may indicate UL subframes for the UE102to transmit information to the eNB160. For proper communication on a cell, the UE102and the eNB160may apply the same UL-DL configuration128on the same cell. However, different UL-DL configurations128may be applied on different cells (e.g., PCell and SCell(s)).

The UL-DL configurations128may also indicate PDSCH HARQ-ACK associations (as illustrated in Table (3) above, for example). A PDSCH HARQ-ACK association may specify a particular (PDSCH HARQ-ACK) timing for sending HARQ-ACK information corresponding to a PDSCH. For example, the HARQ-ACK generation module132may generate HARQ-ACK information corresponding to a PDSCH based on whether a signal (e.g., data) in the PDSCH was correctly received or not. A PDSCH HARQ-ACK association may specify a reporting subframe in which the UE102reports (e.g., transmits) the HARQ-ACK information corresponding to the PDSCH. The reporting subframe may be determined based on the subframe that includes the PDSCH.

The UE UL-DL configuration determination module130may determine which of the UL-DL configuration(s)128for the UE102to apply for one or more cells. For example, the UE102may receive one or more RRC configuration (e.g., SIB-1 broadcasted information or dedicated signaling) indicating UL-DL configuration(s)128for a PCell and for one or more SCells. For instance, a PCell and an SCell may be utilized in carrier aggregation. The UE UL-DL configuration determination module130may determine which UL-DL configuration128is assigned to the PCell and which UL-DL configuration128is assigned to the SCell. The UL-DL configurations128for the PCell and SCell(s) may be the same or different.

The UE reporting subframe determination module134may determine a reporting subframe for sending HARQ-ACK information. For example, the UE reporting subframe determination module134may determine a HARQ-ACK reporting subframe in which the UE102sends SCell HARQ-ACK information (e.g., PDSCH HARQ-ACK information corresponding to an SCell). For example, the UE reporting subframe determination module134may determine a reporting subframe for sending SCell HARQ-ACK information on the PCell according to the timing reference described above in Table (3). For instance, Table (3) above (e.g., the PDSCH HARQ-ACK association table) gives the location of a corresponding PDSCH by the index set K:{k0, k1, . . . , kM−1} for a subframe (e.g., UL subframe) number n, where the HARQ-ACK of a PDSCH in subframe n−k (e.g., n−k1) is reported in UL subframe n. The UE102may send the SCell HARQ-ACK information in the determined HARQ-ACK reporting subframe.

The format application module184may apply a particular format to the HARQ-ACK information in certain cases. For example, the format application module184may determine which of cases I-VI described above are applicable. For instance, if one of cases III-VI is applicable, the format application module184may perform PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter as described above. In particular, the format application module184may apply one or more of the approaches, procedures, ways and techniques described above in accordance with a corresponding case. For instance, the format application module184may multiplex HARQ-ACK information corresponding to one or more of the PCell and SCell as described above.

In some implementations, the UE102may receive a channel selection determination scheme indicator from the eNB160. For example, the channel selection determination scheme indicator may specify one or more of the approaches, procedures, ways and techniques described above. For instance, the UE102may receive a channel selection determination scheme indicator that indicates whether the channel selection to be performed is based on a total number of associated subframes (e.g., Mtotal) between the PCell and SCell or a maximum number of associated subframes (e.g., Mmax) between the PCell and SCell. The format application module184may apply a particular format in accordance with the specified one or more of the approaches, procedures, ways and techniques described above. This may allow the UE102and the eNB160to utilize the same channel selection determination scheme in implementations where multiple channel selection determination schemes may be applied.

The UE operations module124may provide information148to the one or more receivers120. For example, the UE operations module124may inform the receiver(s)120when or when not to receive transmissions based on the UL-DL configurations128.

The UE operations module124may provide information138to the demodulator114. For example, the UE operations module124may inform the demodulator114of a modulation pattern anticipated for transmissions from the eNB160.

The UE operations module124may provide information136to the decoder108. For example, the UE operations module124may inform the decoder108of an anticipated encoding for transmissions from the eNB160.

The UE operations module124may provide information142to the encoder150. The information142may include data to be encoded and/or instructions for encoding. For example, the UE operations module124may instruct the encoder150to encode transmission data146and/or other information142. The other information142may include PDSCH HARQ-ACK information.

The encoder150may encode transmission data146and/or other information142provided by the UE operations module124. For example, encoding the data146and/or other information142may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder150may provide encoded data152to the modulator154.

The UE operations module124may provide information144to the modulator154. For example, the UE operations module124may inform the modulator154of a modulation type (e.g., constellation mapping) to be used for transmissions to the eNB160. The modulator154may modulate the encoded data152to provide one or more modulated signals156to the one or more transmitters158.

The UE operations module124may provide information140to the one or more transmitters158. This information140may include instructions for the one or more transmitters158. For example, the UE operations module124may instruct the one or more transmitters158when to transmit a signal to the eNB160. In some configurations, this may be based on a UL-DL configuration128. For instance, the one or more transmitters158may transmit during an UL subframe. The one or more transmitters158may upconvert and transmit the modulated signal(s)156to one or more eNBs160.

The eNB160may include one or more transceivers176, one or more demodulators172, one or more decoders166, one or more encoders109, one or more modulators113, a data buffer162and an eNB operations module182. For example, one or more reception and/or transmission paths may be implemented in an eNB160. For convenience, only a single transceiver176, decoder166, demodulator172, encoder109and modulator113are illustrated in the eNB160, though multiple parallel elements (e.g., transceivers176, decoders166, demodulators172, encoders109and modulators113) may be implemented.

The transceiver176may include one or more receivers178and one or more transmitters117. The one or more receivers178may receive signals from the UE102using one or more antennas180a-n. For example, the receiver178may receive and downconvert signals to produce one or more received signals174. The one or more received signals174may be provided to a demodulator172. The one or more transmitters117may transmit signals to the UE102using one or more antennas180a-n. For example, the one or more transmitters117may upconvert and transmit one or more modulated signals115.

The demodulator172may demodulate the one or more received signals174to produce one or more demodulated signals170. The one or more demodulated signals170may be provided to the decoder166. The eNB160may use the decoder166to decode signals. The decoder166may produce one or more decoded signals164,168. For example, a first eNB-decoded signal164may comprise received payload data, which may be stored in a data buffer162. A second eNB-decoded signal168may comprise overhead data and/or control data. For example, the second eNB-decoded signal168may provide data (e.g., PDSCH HARQ-ACK information) that may be used by the eNB operations module182to perform one or more operations.

In general, the eNB operations module182may enable the eNB160to communicate with the one or more UEs102. The eNB operations module182may include one or more of UL-DL configurations194, an eNB reporting subframe determination module198, an eNB UL-DL configuration determination module196, an eNB feedback parameter determination module151and an interpreter107. In some implementations, the eNB operations module182may also include a scheme signaling module153.

The UL-DL configurations194may specify a set of UL-DL configurations that may be used for communication between the eNB160and the UE(s)102. Examples of UL-DL configurations194include the UL-DL configurations0-6illustrated in Table (1) above. The UL-DL configurations194may specify UL and DL subframes for communication with the UE(s)102. For example, the UL-DL configurations194may indicate DL subframes for the eNB160to send information to the UE(s)102and may indicate UL subframes for the eNB160to receive information from the UE(s)102. For proper communication on a cell, the UE102and the eNB160may apply the same UL-DL configuration194on the same cell. However, different UL-DL configurations194may be applied on different cells (e.g., PCell and SCell(s)).

The UL-DL configurations194may also indicate PDSCH HARQ-ACK associations (as illustrated in Table (3), for example). A PDSCH HARQ-ACK association may specify a particular (PDSCH HARQ-ACK) timing for receiving HARQ-ACK information corresponding to a PDSCH. A PDSCH HARQ-ACK association may specify a reporting subframe in which the UE102reports (e.g., transmits) the HARQ-ACK information corresponding to the PDSCH to the eNB160. The reporting subframe may be determined based on the subframe that includes the PDSCH sent by the eNB160.

The eNB UL-DL configuration determination module196may determine which of the UL-DL configuration(s)194for the UE102to apply for one or more cells. For example, the eNB160may send one or more RRC configuration (e.g., SIB-1 broadcasted information or dedicated signaling) indicating UL-DL configuration(s)194for a PCell and for one or more SCells. For instance, a PCell and an SCell may be utilized in carrier aggregation. The eNB UL-DL configuration determination module196may assign UL-DL configuration(s)194to the PCell and to the SCell. The eNB160may signal one or more of these assignments to a UE102. The UL-DL configurations194for the PCell and SCell(s) may be the same or different.

The eNB reporting subframe determination module198may determine a reporting subframe for receiving HARQ-ACK information. For example, the eNB reporting subframe determination module198may determine a HARQ-ACK reporting subframe in which the eNB160receives SCell PDSCH HARQ-ACK information (e.g., PDSCH HARQ-ACK information corresponding to an SCell) from a UE102. For example, the eNB reporting subframe determination module198may determine a reporting subframe for receiving SCell HARQ-ACK information on the PCell according to the timing reference described above in Table (3). For instance, Table (3) above (e.g., the PDSCH HARQ-ACK association table) gives the location of a corresponding PDSCH by the index set K:{k0, k1, . . . , kM−1}, for a subframe (e.g., UL subframe) number n, where the HARQ-ACK of a PDSCH in subframe n−k (e.g., n−k1) is reported in UL subframe n. The eNB160may receive the SCell HARQ-ACK information in the determined HARQ-ACK reporting subframe.

Additionally or alternatively, in some implementations, one of multiple channel selection determination schemes may be utilized. In these implementations, the eNB160may signal which scheme is utilized. For example, the eNB160may send a channel selection determination scheme indicator that indicates whether the channel selection to be performed is based on a total number of associated subframes (e.g., Mtotal) between the PCell and SCell or a maximum number of associated subframes (e.g., Mmax) between the PCell and SCell. Additionally or alternatively, the channel selection determination scheme indicator may indicate one or more of the approaches, procedures, way and techniques described above (for application by the UE102in performing channel selection, for example). In other implementations, only one channel selection determination scheme may be utilized by the eNB160and UE102. In these implementations, the eNB160may not signal a channel selection determination scheme.

The interpreter107may interpret formats of the HARQ-ACK information in certain cases. For example, the interpreter107may interpret Format 1b with channel selection. For instance, the interpreter107may interpret received HARQ-ACK information based on PUCCH Format 1b with channel selection in accordance with one or more of the approaches, procedures, techniques and ways described above.

The eNB operations module182may provide information190to the one or more receivers178. For example, the eNB operations module182may inform the receiver(s)178when or when not to receive transmissions based on a UL-DL configuration194for a given cell.

The eNB operations module182may provide information188to the demodulator172. For example, the eNB operations module182may inform the demodulator172of a modulation pattern anticipated for transmissions from the UE(s)102.

The eNB operations module182may provide information186to the decoder166. For example, the eNB operations module182may inform the decoder166of an anticipated encoding for transmissions from the UE(s)102.

The eNB operations module182may provide information101to the encoder109. The information101may include data to be encoded and/or instructions for encoding. For example, the eNB operations module182may instruct the encoder109to encode transmission data105and/or other information101. The other information101may include one or more of RRC configuration (e.g., SIB-1 broadcasted information or dedicated signaling) (e.g., PCell configuration indicator, SCell configuration indicator), a channel scheme determination indicator and a feedback parameter determination scheme indicator, for example.

The encoder109may encode transmission data105and/or other information101provided by the eNB operations module182. For example, encoding the data105and/or other information101may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder109may provide encoded data111to the modulator113. The transmission data105may include network data to be relayed to the UE102.

The eNB operations module182may provide information103to the modulator113. This information103may include instructions for the modulator113. For example, the eNB operations module182may inform the modulator113of a modulation type (e.g., constellation mapping) to be used for transmissions to the UE(s)102. The modulator113may modulate the encoded data111to provide one or more modulated signals115to the one or more transmitters117.

The eNB operations module182may provide information192to the one or more transmitters117. This information192may include instructions for the one or more transmitters117. For example, the eNB operations module182may instruct the one or more transmitters117when to (or when not to) transmit a signal to the UE(s)102. In some implementations, this may be based on an UL-DL configuration194. The one or more transmitters117may upconvert and transmit the modulated signal(s)115to one or more UEs102.

It should be noted that a DL subframe may be transmitted from the eNB160to one or more UEs102and that an UL subframe may be transmitted from one or more UEs102to the eNB160. Furthermore, both the eNB160and the one or more UEs102may transmit data in a standard special subframe.

It should be noted that one or more of the elements or parts thereof included in the eNB(s)160and UE(s)102may be implemented in hardware. For example, one or more of these elements or parts thereof may be implemented as a chip, circuitry or hardware components, etc. It should also be noted that one or more of the functions or methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.

FIG. 2is a flow diagram illustrating one configuration of a method200for sending feedback information. A UE102may determine202a PCell feedback parameter corresponding to a PCell (for an uplink subframe on the PCell, for instance). For example, the UE102may determine202the MCof the PCell in accordance with the above description. For instance, the PCell feedback parameter (e.g., MCof the PCell) may be the M corresponding to the PCell configuration signaled to the UE102from the eNB160as provided by Table (3) above. For example, the UE102may receive a PCell feedback parameter indicator from the eNB160that specifies the PCell feedback parameter.

In some implementations, the UE102may determine204the SCell feedback parameter in accordance with one or more of the approaches described above. Additionally or alternatively, the UE102may receive an SCell feedback parameter indicator from the eNB160that specifies the SCell feedback parameter. The SCell feedback parameter may indicate a number of subframes with a PDSCH HARQ-ACK association for the SCell for a particular UL-DL configuration. For instance, the UE102may determine204the SCell feedback parameter of an SCell as a reference parameter (e.g., MRef). The reference parameter may indicate a number of subframes with a PDSCH HARQ-ACK association for a reference configuration.

In some implementations, the UE102may determine204the SCell feedback parameter based on a number of conflicting subframes (e.g., m) and the reference parameter (e.g., MRef). For example, the UE102may determine the reference parameter (e.g., MRef) as described above and may set the SCell feedback parameter (e.g., MCof the SCell) equal to MEff=MRef−m. In other words, MEffmay be a number of downlink subframes and special subframes with PDSCH HARQ-ACK associations for an SCell that is following a reference configuration, excluding the conflicting subframes. Conflicting subframes may be subframes that are DL subframes or special subframes in the reference configuration and are UL subframes in the SCell configuration.

In some implementations, a similar approach may be applied for cross-carrier scheduling. For example, the UE102may determine204the SCell feedback parameter based on a reference parameter (e.g., MRef) (in addition to or alternatively from a number of conflicting subframes (e.g., m)) when the SCell is cross-carrier scheduled. Alternatively, the UE102may determine204the SCell feedback parameter as a scheduling cell parameter (e.g., MSchedulingCell) when the SCell is cross-carrier scheduled. MSchedulingCellmay be a number of subframes with a PDSCH HARQ-ACK association for a scheduling cell (UL-DL) configuration. In a case where the scheduling cell is not the PCell, the (MCof the) PDSCH reporting reference configuration of the scheduling cell may be used instead of the (MCof the) scheduling cell configuration.

In another implementation, the feedback parameter MCof the SCell may be MEff—SchedulingCellwhere MEff—SchedulingCellis the MEffof the scheduling cell (where MEffis the effective M of the scheduling cell (e.g., the PCell) configuration for which the PDSCH HARQ-ACK timing is followed, excluding the conflicting subframes, for example). In this context, a conflicting subframe may be a subframe that is a DL or special subframe in the scheduling cell configuration and is an UL subframe in the SCell configuration. In a case where the scheduling cell is not the PCell, the (MCof the) PDSCH reporting reference configuration of the scheduling cell may be used instead of the (MCof the) scheduling cell configuration. The remaining method200steps may be performed when the PCell feedback parameter and the SCell feedback parameter are different. For example, the UE102may determine which of cases I-VI described above are applicable. For instance, in case I, UL-DL configuration5is at least one of the PCell configuration and SCell configuration. In case I, the UE102may not perform channel selection. In case II, the PCell feedback parameter (e.g., MCof the PCell) and the SCell feedback parameter (e.g., MCof the SCell) are the same. In case II, known techniques (in Rel-10) may be reused. For cases III-VI, however, the following method200steps may be applied by a UE102.

The UE102may perform206PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. This may be done in accordance with the above description. For example, the UE102may perform206PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter for one of cases III, IV, V and VI as described above. In particular, the UE102may apply one or more of the approaches, procedures, ways and techniques described above.

For example, in case III, where only the PCell has HARQ-ACK to be reported (e.g., the PCell feedback parameter (e.g., MCof the PCell) is greater than zero and the SCell feedback parameter (e.g., MCof the SCell) is zero in an uplink subframe), performing206PUCCH Format 1b channel selection may include performing single-cell PUCCH Format 1b channel selection as described above (e.g., PUCCH reporting methods or techniques for one configured serving cell, for example, PUCCH Format 1a/1b or PUCCH Format 1b with channel selection may be performed based on the tables defined in section 10.1.3.1 in 3GPP TS 36.213). Furthermore, in case IV, where only the SCell has HARQ-ACK to be reported (e.g., the PCell feedback parameter (e.g., M of the PCell) is zero and the SCell feedback parameter (e.g., M of the SCell) is greater than zero in an uplink subframe), performing206PUCCH Format 1b channel selection may include performing single-cell PUCCH Format 1b channel selection as described above.

For instance, in case V or case VI, the channel selection may be based on a total number of associated subframes (e.g., Mtotalbetween the PCell and SCell as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a maximum number of associated subframes (e.g., Mmax) between the PCell and SCell as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a number of associated subframes of the PCell, where sending208HARQ-ACK information includes sending a first number of SCell HARQ-ACK bits that is the same as or different from (e.g., less than or equal to) a second number of PCell HARQ-ACK bits as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a channel selection table. For instance, the UE102may select a channel selection table based on the PCell feedback parameter and the SCell feedback parameter. The channel selection table may be a channel selection table as defined by 3GPP Rel-10 specifications or may be another (new) channel selection table (not defined by Rel-10 specifications) as described above.

It should be noted that in some implementations, the UE102may receive a channel selection determination scheme from the eNB160. For example, the channel selection determination scheme may specify one or more of the approaches, procedures, ways and techniques described above. This may allow the UE102and the eNB160to utilize the same channel selection determination scheme in implementations where multiple channel selection determination schemes may be applied.

It should be noted that UE102may determine HARQ-ACK information. For example, the UE102may determine whether one or more PDSCH signals (e.g., voice, data) were correctly received on at least one of the PCell and the SCell. For instance, the UE102may generate an Acknowledgement (ACK) bit for each packet that is correctly received on a PDSCH. However, the UE102may generate a Negative Acknowledgement (NACK) bit for each packet that is not correctly received on a PDSCH.

The UE102may send208the HARQ-ACK information based on the channel selection. For example, the channel selection may specify how the HARQ-ACK information is multiplexed and reported in an uplink report.

FIG. 3is a flow diagram illustrating one configuration of a method300for receiving feedback information. An eNB160may determine302a PCell feedback parameter corresponding to a PCell (for an uplink subframe on the PCell, for instance). For example, the eNB160may determine302the MCof the PCell in accordance with the above description. For instance, the PCell feedback parameter (e.g., MCof the PCell) may be the M corresponding to the PCell configuration determined by the eNB160as provided by Table (3) above. In some implementations, the eNB160may send a PCell feedback parameter indicator to the UE102that specifies the PCell feedback parameter.

The eNB160may determine304an SCell feedback parameter corresponding to an SCell (for the given uplink subframe on the PCell, for instance). For example, the eNB160may determine304the SCell feedback parameter (e.g., the M of the SCell) in accordance with the above description. For instance, the eNB160may determine304the SCell feedback parameter based on the PCell configuration and the SCell configuration. For example, the eNB160may determine304the SCell feedback parameter based on whether a set of DL subframes for the SCell configuration is a subset of a set of DL subframes for the PCell configuration (case A), whether a set of DL subframes for the PCell configuration is a subset of a set of DL subframes for the SCell configuration (case B) or neither (case C). In some implementations, the eNB160may send an SCell feedback parameter indicator to the UE102that specifies the SCell feedback parameter.

In some implementations, the eNB160may determine304the SCell feedback parameter in accordance with one or more of the approaches described above. The SCell feedback parameter may indicate a number of subframes with a PDSCH HARQ-ACK association for the SCell for a particular UL-DL configuration. For instance, the eNB160may determine304the SCell feedback parameter of an SCell as a reference parameter (e.g., MRef) The reference parameter may indicate a number of subframes with a PDSCH HARQ-ACK association for a reference configuration.

In some implementations, the eNB160may determine304the SCell feedback parameter based on a number of conflicting subframes (e.g., m) and the reference parameter (e.g., MRef). For example, the eNB160may determine the reference parameter (e.g., MRef) as described above and may set the SCell feedback parameter (e.g., MCof the SCell) equal to MEff=MRef−m. In other words, MEffmay be a number of downlink subframes and special subframes with PDSCH HARQ-ACK associations for an SCell that is following a reference configuration, excluding the conflicting subframes. Conflicting subframes may be subframes that are DL subframes or special subframes in the reference configuration and are UL subframes in the SCell configuration.

In some implementations, a similar approach may be applied for cross-carrier scheduling. For example, the eNB160may determine304the SCell feedback parameter based on a reference parameter (e.g., MRef) (in addition to or alternatively from a number of conflicting subframes (e.g., m)) when the SCell is cross-carrier scheduled. Alternatively, the eNB160may determine304the SCell feedback parameter as a scheduling cell parameter (e.g., MSchedulingCell) when the SCell is cross-carrier scheduled. MSchedulingCellmay be a number of subframes with a PDSCH HARQ-ACK association for a scheduling cell (UL-DL) configuration. In a case where the scheduling cell is not the PCell, the (MCof the) PDSCH reporting reference configuration of the scheduling cell may be used instead of the (MCof the) scheduling cell configuration.

In another implementation, the feedback parameter MCof the SCell may be MEff—SchedulingCell, where MEff—SchedulingCellis the MEffof the scheduling cell (where MEffis the effective M of the scheduling cell (e.g., the PCell) configuration for which the PDSCH HARQ-ACK timing is followed, excluding the conflicting subframes, for example). In this context, a conflicting subframe may be a subframe that is a DL or special subframe in the scheduling cell configuration and is an UL subframe in the SCell configuration. In a case where the scheduling cell is not the PCell, the (MCof the) PDSCH reporting reference configuration of the scheduling cell may be used instead of the (MCof the) scheduling cell configuration. The remaining method300steps may be performed when the PCell feedback parameter and the SCell feedback parameter are different. For example, the eNB160may determine which of cases I-VI described above are applicable. For instance, in case I, UL-DL configuration5is at least one of the PCell configuration and SCell configuration. In case I, the eNB160may not perform channel selection. In case II, the PCell feedback parameter (e.g., MCof the PCell) and the SCell feedback parameter (e.g., MCof the SCell) are the same. In case II, known techniques (in Rel-10) may be reused. For cases III-VI, however, the following method300steps may be applied by an eNB160.

The eNB160may perform306PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter. This may be done in accordance with the above description. For example, the eNB160may perform306PUCCH Format 1b channel selection based on the PCell feedback parameter and the SCell feedback parameter for one of cases III, IV, V and VI as described above. In particular, the eNB160may apply one or more of the approaches, procedures, ways and techniques described above.

For example, in case III, where only the PCell has HARQ-ACK to be reported (e.g., the PCell feedback parameter (e.g., MCof the PCell) is greater than zero and the SCell feedback parameter (e.g., MCof the SCell) is zero in an uplink subframe), performing306PUCCH Format 1b channel selection may include performing single-cell PUCCH Format 1b channel selection as described above (e.g., PUCCH reporting methods or techniques for one configured serving cell, for example, PUCCH Format 1a/1b or PUCCH Format 1b with channel selection may be performed based on the tables defined in section 10.1.3.1 in 3GPP TS 36.213). Furthermore, in case IV, where only the SCell has HARQ-ACK to be reported (e.g., the PCell feedback parameter (e.g., MCof the PCell) is zero and the SCell feedback parameter (e.g., MCof the SCell) is greater than zero in an uplink subframe), performing306PUCCH Format 1b channel selection may include performing single-cell PUCCH Format 1b channel selection as described above.

For instance, in case V or case VI, the channel selection may be based on a total number of associated subframes (e.g., Mtotal) between the PCell and SCell as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a maximum number of associated subframes (e.g., Mmax) between the PCell and SCell as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a number of associated subframes of the PCell, where receiving308HARQ-ACK information includes receiving a first number of SCell HARQ-ACK bits that is the same as or different from (e.g., less than or equal to) a second number of PCell HARQ-ACK bits as described above. Additionally or alternatively, in case V or case VI, the channel selection may be based on a channel selection table. For instance, the eNB160may select a channel selection table based on the PCell feedback parameter and the SCell feedback parameter. The channel selection table may be a channel selection table as defined by Rel-10 specifications or may be another (new) channel selection table (not defined by Rel-10 specifications) as described above.

It should be noted that in some implementations, the eNB160may send a channel selection determination scheme to the UE102. For example, the channel selection determination scheme may specify one or more of the approaches, procedures, ways and techniques described above. This may allow the eNB160and the UE102to utilize the same channel selection determination scheme in implementations where multiple channel selection determination schemes may be applied.

It should be noted that eNB160may send PDSCH signals (e.g., voice, data) to the UE102. For example, the eNB160may send a voice call to a UE102in addition to or alternatively from data (e.g., text messages, Internet browsing data, etc.) via a PDSCH.

The eNB160may receive308HARQ-ACK information based on the channel selection. For example, the channel selection may specify how the received HARQ-ACK information is multiplexed and reported in an uplink report. The eNB160may interpret the received308HARQ-ACK information based on the channel selection.

FIG. 4is a diagram illustrating one example of a radio frame435that may be used in accordance with the systems and methods disclosed herein. This radio frame435structure may be applicable in TDD approaches. Each radio frame435may have a length of Tf=307200·Ts=10 ms, where Tfis a radio frame435duration and Tsis a time unit equal to

1(15000×2048)
seconds. The radio frame435may include two half-frames433, each having a length of 153600·Ts=5 ms. Each half-frame433may include five subframes423a-e,423f-jeach having a length of 30720·Ts=1 ms.

In Table (1) above, for each subframe in a radio frame, “D” indicates that the subframe is reserved for downlink transmissions, “U” indicates that the subframe is reserved for uplink transmissions and “S” indicates a special subframe with three fields: a downlink pilot time slot (DwPTS), a guard period (GP) and an uplink pilot time slot (UpPTS). The length of DwPTS and UpPTS is given in Table (30) (from Table 4.2-1 of 3GPP TS 36.211) subject to the total length of DwPTS, GP and UpPTS being equal to 30720 Ts=1 ms. Table (5) illustrates several configurations of (standard) special subframes. Each subframe i is defined as two slots, 2i and 2i+1 of length Tsiot=15360·Ts=0.5 ms in each subframe. In Table (30), “cyclic prefix” is abbreviated as “CP” and “configuration” is abbreviated as “Config” for convenience.

UL-DL configurations with both 5 ms and 10 ms downlink-to-uplink switch-point periodicity are supported. In the case of 5 ms downlink-to-uplink switch-point periodicity, the special subframe exists in both half-frames. In the case of 10 ms downlink-to-uplink switch-point periodicity, the special subframe exists in the first half-frame only. Subframes0and5and DwPTS may be reserved for downlink transmission. UpPTS and the subframe immediately following the special subframe may be reserved for uplink transmission.

In accordance with the systems and methods disclosed herein, some types of subframes423that may be used include a downlink subframe, an uplink subframe and a special subframe431. In the example illustrated inFIG. 4, which has a 5 ms periodicity, two standard special subframes431a-bare included in the radio frame435.

The first special subframe431aincludes a downlink pilot time slot (DwPTS)425a, a guard period (GP)427aand an uplink pilot time slot (UpPTS)429a. In this example, the first standard special subframe431ais included in subframe one423b. The second standard special subframe431bincludes a downlink pilot time slot (DwPTS)425b, a guard period (GP)427band an uplink pilot time slot (UpPTS)429b. In this example, the second standard special subframe431bis included in subframe six423g. The length of the DwPTS425a-band UpPTS429a-bmay be given by Table 4.2-1 of 3GPP TS 36.211 (illustrated in Table (5) above) subject to the total length of each set of DwPTS425, GP427and UpPTS429being equal to 30720·Ts=1 ms.

Each subframe i423a-j(where i denotes a subframe ranging from subframe zero423a(e.g., 0) to subframe nine423j(e.g., 9) in this example) is defined as two slots, 2i and 2i+1 of length Tslot=15360·Ts=0.5 ms in each subframe423. For example, subframe zero (e.g., 0)423amay include two slots, including a first slot.

UL-DL configurations with both 5 ms and 10 ms downlink-to-uplink switch-point periodicity may be used in accordance with the systems and methods disclosed herein.FIG. 4illustrates one example of a radio frame435with 5 ms switch-point periodicity. In the case of 5 ms downlink-to-uplink switch-point periodicity, each half-frame433includes a standard special subframe431a-b. In the case of 10 ms downlink-to-uplink switch-point periodicity, a special subframe may exist in the first half-frame433only.

Subframe zero (e.g., 0)423aand subframe five (e.g., 5)423fand DwPTS425a-bmay be reserved for downlink transmission. The UpPTS429a-band the subframe(s) immediately following the special subframe(s)431a-b(e.g., subframe two423cand subframe seven423h) may be reserved for uplink transmission. It should be noted that, in some implementations, special subframes431may be considered DL subframes in order to determine a number of conflicting subframes.

FIG. 5further illustrates PDSCH HARQ-ACK associations541(e.g., PDSCH HARQ-ACK feedback on PUCCH or PUSCH associations). The PDSCH HARQ-ACK associations541may indicate HARQ-ACK reporting subframes corresponding to subframes for PDSCH transmissions (e.g., subframes in which PDSCH transmissions may be sent and/or received). It should be noted that some of the radio frames illustrated inFIG. 5have been truncated for convenience.

The systems and methods disclosed herein may be applied to one or more of the UL-DL configurations537a-gillustrated inFIG. 5. For example, one or more PDSCH HARQ-ACK associations541corresponding to one of the UL-DL configurations537a-gillustrated inFIG. 5may be applied to communications between a UE102and eNB160. For example, an UL-DL configuration537may be determined (e.g., assigned to, applied to) a PCell. In this case, PDSCH HARQ-ACK associations541may specify PDSCH HARQ-ACK timing (e.g., a HARQ-ACK reporting subframe) for HARQ-ACK feedback transmissions corresponding to the PCell. For SCell HARQ-ACK feedback transmissions, the PDSCH HARQ-ACK associations541corresponding to a reference UL-DL configuration in accordance with the feedback parameters may be utilized. In some instances, the PDSCH HARQ-ACK information may be formatted and reported in an uplink subframe based on Format 1b with channel selection as described above.

FIG. 6is a diagram illustrating examples of PCell and SCell configurations. More specifically, example A645aillustrates a set of DL subframes for an SCell configuration that are a subset of a set of DL subframes for a PCell configuration (e.g., case A). Example B645billustrates a set of DL subframes for a PCell configuration that are a subset of a set of DL subframes for an SCell configuration (e.g., case B).

In accordance with the systems and methods disclosed herein, the SCell PDSCH HARQ-ACK timing (e.g., reports) may follow the PCell configuration if the set of DL subframes indicated by the SCell configuration (as determined based on a SIB-1, for example) is a subset of the DL subframes indicated by the PCell configuration (as determined based on a SIB-1, for example) as dictated by the feedback parameter MC. In this case, all DL subframes in the SCell configuration are also DL subframes in the PCell configuration. It should be noted that the PCell may have extra DL subframes allocated beyond those of the SCell. InFIG. 6, DL subframes are denoted with a “D,” UL subframes are denoted with a “U,” and special subframes (which may include both an UL component and a DL component, for example) are denoted as an “S” for convenience.

In particular,FIG. 6illustrates example A645a, where the set of DL subframes indicated by the SCell configuration is a subset of the DL subframes indicated by the PCell configuration. More specifically, example A645aillustrates PCell configuration two (e.g., “2”)637aand SCell configuration one (e.g., “1”)637b. In example A645a, SCell DL subframes0,1,4,5,6and9are a subset of PCell DL subframes643a.

In accordance with the systems and methods disclosed herein, the SCell PDSCH HARQ-ACK timing (e.g., reports) may follow the SCell configuration if the set of DL subframes indicated by the PCell configuration (as determined based on a SIB-1, for example) is a subset of the DL subframes indicated by the SCell configuration (as determined based on a SIB-1, for example) as dictated by the feedback parameter MC. In this case, all DL subframes in the PCell configuration are also DL subframes in the SCell configuration. It should be noted that the SCell may have extra DL subframes allocated beyond those of the PCell.

In particular,FIG. 6illustrates example B645b, where the set of DL subframes indicated by the PCell configuration is a subset of the DL subframes indicated by the SCell configuration. More specifically, example B645billustrates SCell configuration two (e.g., “2”)637cand PCell configuration one (e.g., “1”)637d. In example B645b, PCell DL subframes0,1,4,5,6and9are a subset of SCell DL subframes643b.

FIG. 7is a diagram illustrating an example of conflicting subframes747between a PCell configuration737band an SCell configuration737a. A conflicting subframe may occur when a subframe in one UL-DL configuration is a DL (or special subframe) and is an UL subframe in another UL-DL configuration. In this example, subframes3and8are conflicting subframes747between SCell configuration one737aand PCell configuration two737b, since subframes3and8are UL subframes in SCell configuration one737aand PCell configuration two737b.

In accordance with the systems and methods disclosed herein, a number of conflicting subframes m may be utilized in some of the approaches described above. For example, the feedback parameter M of an SCell may be defined as MEff, where MEffis the effective M of the reference configuration for which the PDSCH HARQ-ACK timing is followed excluding the conflicting subframes where the PCell configuration or reference configuration includes a DL subframe (or special subframe, for example) and the SCell configuration includes an UL subframe (e.g., MEff=MRef−m). InFIG. 7, DL subframes are denoted with a “D,” UL subframes are denoted with a “U,” and special subframes (which may include both an UL component and a DL component, for example) are denoted as an “S” for convenience.

FIG. 8illustrates various components that may be utilized in a UE802. The UE802described in connection withFIG. 8may be implemented in accordance with the UE102described in connection withFIG. 1. The UE802includes a processor863that controls operation of the UE802. The processor863may also be referred to as a central processing unit (CPU). Memory869, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions865aand data867ato the processor863. A portion of the memory869may also include non-volatile random access memory (NVRAM). Instructions865band data867bmay also reside in the processor863. Instructions865band/or data867bloaded into the processor863may also include instructions865aand/or data867afrom memory869that were loaded for execution or processing by the processor863. The instructions865bmay be executed by the processor863to implement the method200described above.

The UE802may also include a housing that contains one or more transmitters858and one or more receivers820to allow transmission and reception of data. The transmitter(s)858and receiver(s)820may be combined into one or more transceivers818. One or more antennas822a-nare attached to the housing and electrically coupled to the transceiver818.

The various components of the UE802are coupled together by a bus system871, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated inFIG. 8as the bus system871. The UE802may also include a digital signal processor (DSP)873for use in processing signals. The UE802may also include a communications interface875that provides user access to the functions of the UE802. The UE802illustrated inFIG. 8is a functional block diagram rather than a listing of specific components.

FIG. 9illustrates various components that may be utilized in an eNB960. The eNB960described in connection withFIG. 9may be implemented in accordance with the eNB160described in connection withFIG. 1. The eNB960includes a processor977that controls operation of the eNB960. The processor977may also be referred to as a central processing unit (CPU). Memory983, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions979aand data981ato the processor977. A portion of the memory983may also include non-volatile random access memory (NVRAM). Instructions979band data981bmay also reside in the processor977. Instructions979band/or data981bloaded into the processor977may also include instructions979aand/or data981afrom memory983that were loaded for execution or processing by the processor977. The instructions979bmay be executed by the processor977to implement the method300described above.

The eNB960may also include a housing that contains one or more transmitters917and one or more receivers978to allow transmission and reception of data. The transmitter(s)917and receiver(s)978may be combined into one or more transceivers976. One or more antennas980a-nare attached to the housing and electrically coupled to the transceiver976.

The various components of the eNB960are coupled together by a bus system985, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated inFIG. 9as the bus system985. The eNB960may also include a digital signal processor (DSP)987for use in processing signals. The eNB960may also include a communications interface989that provides user access to the functions of the eNB960. The eNB960illustrated inFIG. 9is a functional block diagram rather than a listing of specific components.

FIG. 10is a block diagram illustrating one configuration of a UE1002in which systems and methods for sending feedback information may be implemented. The UE1002includes transmit means1058, receive means1020and control means1024. The transmit means1058, receive means1020and control means1024may be configured to perform one or more of the functions described in connection withFIG. 2andFIG. 8above.FIG. 8above illustrates one example of a concrete apparatus structure ofFIG. 10. Other various structures may be implemented to realize one or more of the functions ofFIG. 2andFIG. 8. For example, a DSP may be realized by software.

FIG. 11is a block diagram illustrating one configuration of an eNB1160in which systems and methods for receiving feedback information may be implemented. The eNB1160includes transmit means1117, receive means1178and control means1182. The transmit means1117, receive means1178and control means1182may be configured to perform one or more of the functions described in connection withFIG. 3FIG. 9above.FIG. 9above illustrates one example of a concrete apparatus structure ofFIG. 11. Other various structures may be implemented to realize one or more of the functions ofFIG. 3andFIG. 9. For example, a DSP may be realized by software.

The term “computer-readable medium” refers to any available medium that can be accessed by a computer or a processor. The term “computer-readable medium,” as used herein, may denote a computer- and/or processor-readable medium that is non-transitory and tangible. By way of example, and not limitation, a computer-readable or processor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

It should be noted that one or more of the methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.