Physical uplink control channel (PUCCH) resource allocation (RA) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission

Technology to provide conditional physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission request-acknowledge (HARQ-ACK) transmission in a subframe n is disclosed. In an example, a user equipment (UE) can include computer circuitry configured to: Receive a downlink control channel within a prior specified subframe, wherein the prior specified subframe occurs in time before the subframe n; recognize a downlink control channel type received within the prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH); determine a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of the PDCCH when the received downlink control channel type is the PDCCH; and determine the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the received downlink control channel type is the EPDCCH.

BACKGROUND

Wireless mobile communication technology uses various standards and protocols to transmit data between a node (e.g., a transmission station) and a wireless device (e.g., a mobile device). Some wireless devices communicate using orthogonal frequency-division multiple access (OFDMA) in a downlink (DL) transmission and single carrier frequency division multiple access (SC-FDMA) in an uplink (UL) transmission. Standards and protocols that use orthogonal frequency-division multiplexing (OFDM) for signal transmission include the third generation partnership project (3GPP) long term evolution (LTE), the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard (e.g., 802.16e, 802.16m), which is commonly known to industry groups as WiMAX (Worldwide interoperability for Microwave Access), and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi.

In 3GPP radio access network (RAN) LTE systems, the node can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), which communicates with the wireless device, known as a user equipment (UE). The downlink (DL) transmission can be a communication from the node (e.g., eNodeB) to the wireless device (e.g., UE), and the uplink (UL) transmission can be a communication from the wireless device to the node.

In LTE, data can be transmitted from the eNodeB to the UE via a physical downlink shared channel (PDSCH). A physical uplink control channel (PUCCH) can be used to acknowledge that data was received. Downlink and uplink channels or transmissions can use time-division duplexing (TDD) or frequency-division duplexing (FDD). Time-division duplexing (TDD) is an application of time-division multiplexing (TDM) to separate downlink and uplink signals. In TDD, downlink signals and uplink signals may be carried on a same carrier frequency (i.e., shared carrier frequency) where the downlink signals use a different time interval from the uplink signals, so the downlink signals and the uplink signals do not generate interference for each other. TDM is a type of digital multiplexing in which two or more bit streams or signals, such as a downlink or uplink, are transferred apparently simultaneously as sub-channels in one communication channel, but are physically transmitted on different resources. In frequency-division duplexing (FDD), an uplink transmission and a downlink transmission can operate using different frequency carriers (i.e. separate carrier frequency for each transmission direction). In FDD, interference can be avoided because the downlink signals use a different frequency carrier from the uplink signals.

DETAILED DESCRIPTION

Example Embodiments

The communication of data on the physical downlink shared channel (PDSCH) can be controlled via a control channel, referred to as a physical downlink control channel (PDCCH). The PDCCH can be used for downlink (DL) and uplink (UL) resource assignments, transmit power commands, and paging indicators. The PDSCH scheduling grant can be designated to a particular wireless device (e.g., UE) for dedicated PDSCH resource allocation to carry UE-specific traffic, or the PDSCH scheduling grant can be designated to all wireless devices in the cell for common PDSCH resource allocation to carry broadcast control information such as system information or paging.

In one example, the PDCCH and PDSCH can represent elements of a radio frame structure transmitted on the physical (PHY) layer in a downlink transmission between a node (e.g., eNodeB) and the wireless device (e.g., UE) using a generic 3GPP long term evolution (LTE) frame structure, as illustrated inFIG. 1.

FIG. 1illustrates a downlink radio frame structure type 2. In the example, a radio frame100of a signal used to transmit the data can be configured to have a duration, Tf, of 10 milliseconds (ms). Each radio frame can be segmented or divided into ten subframes110ithat are each 1 ms long. Each subframe can be further subdivided into two slots120aand120b, each with a duration, Tslot, of 0.5 ms. The first slot (#0)120acan include a legacy physical downlink control channel (PDCCH)160and/or a physical downlink shared channel (PDSCH)166, and the second slot (#1)120bcan include data transmitted using the PDSCH.

Each slot for a component carrier (CC) used by the node and the wireless device can include multiple resource blocks (RBs)130a,130b,130i,130m, and130nbased on the CC frequency bandwidth. The CC can have a carrier frequency having a bandwidth and center frequency. Each subframe of the CC can include downlink control information (DCI) found in the legacy PDCCH. The legacy PDCCH in the control region can include one to three columns of the first OFDM symbols in each subframe or RB, when a legacy PDCCH is used. The remaining 11 to 13 OFDM symbols (or 14 OFDM symbols, when legacy PDCCH is not used) in the subframe may be allocated to the PDSCH for data (for short or normal cyclic prefix).

The control region can include physical control format indicator channel (PCFICH), physical hybrid automatic repeat request (hybrid-ARQ) indicator channel (PHICH), and the PDCCH. The control region has a flexible control design to avoid unnecessary overhead. The number of OFDM symbols in the control region used for the PDCCH can be determined by the control channel format indicator (CFI) transmitted in the physical control format indicator channel (PCFICH). The PCFICH can be located in the first OFDM symbol of each subframe. The PCFICH and PHICH can have priority over the PDCCH, so the PCFICH and PHICH are scheduled prior to the PDCCH.

Each RB (physical RB or PRB)130ican include 12-15 kHz subcarriers136(on the frequency axis) and 6 or 7 orthogonal frequency-division multiplexing (OFDM) symbols132(on the time axis) per slot. The RB can use seven OFDM symbols if a short or normal cyclic prefix is employed. The RB can use six OFDM symbols if an extended cyclic prefix is used. The resource block can be mapped to 84 resource elements (REs)140iusing short or normal cyclic prefixing, or the resource block can be mapped to 72 REs (not shown) using extended cyclic prefixing. The RE can be a unit of one OFDM symbol142by one subcarrier (i.e., 15 kHz)146.

Each RE can transmit two bits150aand150bof information in the case of quadrature phase-shift keying (QPSK) modulation. Other types of modulation may be used, such as 16 quadrature amplitude modulation (QAM) or 64 QAM to transmit a greater number of bits in each RE, or bi-phase shift keying (BPSK) modulation to transmit a lesser number of bits (a single bit) in each RE. The RB can be configured for a downlink transmission from the eNodeB to the UE, or the RB can be configured for an uplink transmission from the UE to the eNodeB.

Each wireless device may use at least one bandwidth. The bandwidth may be referred to as a signal bandwidth, carrier bandwidth, or component carrier (CC) bandwidth, as illustrated inFIG. 2. For example, the LTE CC bandwidths can include: 1.4 MHz310, 3 MHz312, 5 MHz314, 10 MHz316, 15 MHz318, and 20 MHz320. The 1.4 MHz CC can include 6 RBs comprising 72 subcarriers. The 3 MHz CC can include 15 RBs comprising 180 subcarriers. The 5 MHz CC can include 25 RBs comprising 300 subcarriers. The 10 MHz CC can include 50 RBs comprising 600 subcarriers. The 15 MHz CC can include 75 RBs comprising 900 subcarriers. The 20 MHz CC can include 100 RBs comprising 1200 subcarriers.

For each UE, a CC can be defined as a primary cell (PCell). Different UEs may not necessarily use a same CC as their PCell. The PCell can be regarded as an anchor carrier for the UE and the PCell can thus be used for control signaling functionalities, such as radio link failure monitoring, hybrid automatic repeat request-acknowledgement (HARQ-ACK), and physical uplink control channel (PUCCH) resource allocations (RA). If more than one CC is configured for a UE, the additional CCs can be denoted as secondary cells (SCells) for the UE.

The data carried on the PDCCH can be referred to as downlink control information (DCI). Multiple wireless devices can be scheduled in one subframe of a radio frame. Therefore, multiple DCI messages can be sent using multiple PDCCHs. The DCI information in a PDCCH can be transmitted using one or more control channel elements (CCE). A CCE can be comprised of a group of resource element groups (REGs). A legacy CCE can include up to nine REGs. Each legacy REG can be comprised of four resource elements (REs). Each resource element can include two bits of information when quadrature modulation is used. Therefore, a legacy CCE can include up to 72 bits of information. When more than 72 bits of information are needed to convey the DCI message, multiple CCEs can be employed. The use of multiple CCEs can be referred to as an aggregation level. In one example, the aggregation levels can be defined as 1, 2, 4 or 8 consecutive CCEs allocated to one legacy PDCCH.

The legacy PDCCH can create limitations to advances made in other areas of wireless communication. For example, mapping of CCEs to subframes in OFDM symbols can typically be spread over the control region to provide frequency diversity. However, no beam forming diversity may be possible with the current mapping procedures of the PDCCH. Moreover, the capacity of the legacy PDCCH may not be sufficient for advanced control signaling.

To overcome the limitations of the legacy PDCCH, an enhanced PDCCH (EPDCCH) can use the REs in an entire PRB or PRB pair (where a PRB pair can be two contiguous PRBs using the same subcarrier's subframe), instead of just the first one to three columns of OFDM symbols in a first slot PRB in a subframe as in the legacy PDCCH. Accordingly, the EPDCCH can be configured with increased capacity to allow advances in the design of cellular networks and to minimize currently known challenges and limitations.

Unlike the legacy PDCCH, the EPDCCH can be mapped to the same REs or region in a PRB as the PDSCH, but in different PRBs. In an example, the PDSCH and the EPDCCH may not be multiplexed within a same PRB (or a same PRB pair). Thus if one PRB (or one PRB pair) contains an EPDCCH, the unused REs in the PRB (or PRB pair) may be blanked, since the REs may not be used for the PDSCH.

For Long Term Evolution (LTE) time division duplex (TDD) system, two types of downlink control channels (e.g., PDCCH and EPDCCH) may coexist within a certain bundling window. A PUCCH resource allocation method can be defined when the bundling window uses both the PDCCH and the EPDCCH.

Referring back toFIG. 2, a component carrier can be used to carry channel information via a radio frame structure transmitted on the physical (PHY) layer in a uplink transmission between a node (e.g., eNodeB) and the wireless device (e.g., UE) using a generic long term evolution (LTE) frame structure, as illustrated inFIG. 3. While an LTE frame structure is illustrated, a frame structure for another type of communication standard using SC-FDMA or OFDMA may also be used.

FIG. 3illustrates an uplink radio frame structure. A similar structure can be used for a downlink radio frame structure using OFDMA, as illustratedFIG. 1. In the example shown inFIG. 3, a radio frame100of a signal used to transmit control information or data can be configured to have a duration. Tf of 10 milliseconds (ms). Each radio frame can be segmented or divided into ten subframes110ithat are each 1 ms long. Each subframe can be further subdivided into two slots120aand120b, each with a duration, Tslotof 0.5 ms. Each slot for a component carrier (CC) used by the wireless device and the node can include multiple resource blocks (RBs)330a,330b,330i,330m, and330nbased on the CC frequency bandwidth. Each RB (physical RB or PRB)330ican include 12-15 kHz subcarriers336(on the frequency axis) and 6 or 7 SC-FDMA symbols332(on the time axis) per subcarrier. The RB can use seven SC-FDMA symbols if a short or normal cyclic prefix is employed. The RB can use six SC-FDMA symbols if an extended cyclic prefix is used. The resource block can be mapped to 84 resource elements (REs)140iusing short or normal cyclic prefixing, or the resource block can be mapped to 72 REs (not shown) using extended cyclic prefixing. The RE can be a unit of one SC-FDMA symbol342by one subcarrier (i.e., 15 kHz)146. Each RE can transmit two bits150aand150bof information in the case of quadrature phase-shift keying (QPSK) modulation. Other types of modulation may be used, such as 16 quadrature amplitude modulation (QAM) or 64 QAM to transmit a greater number of bits in each RE, or bi-phase shift keying (BPSK) modulation to transmit a lesser number of bits (a single bit) in each RE. The RB can be configured for an uplink transmission from the wireless device to the node.

An uplink signal or channel can include data on a Physical Uplink Shared CHannel (PUSCH) or control information on a Physical Uplink Control CHannel (PUCCH). In LTE, the uplink physical channel (PUCCH) carrying uplink control information (UCI) can include channel state information (CSI) reports, Hybrid Automatic Retransmission reQuest (HARQ) ACKnowledgment/Negative ACKnowledgment (ACK/NACK) and uplink scheduling requests (SR).

The wireless device (e.g., UE) can provide HARQ-ACK feedback for a PDSCH using a PUCCH. The PUCCH can support multiple formats (i.e., PUCCH format) with various modulation and coding schemes (MCS), as shown for LTE in Table 1. Similar information to Table 1 can be shown in 3GPP LTE standard Release 11 (e.g., V11.2.0 (2013-02)) Technical Specification (TS) 36.211 Table 5.4-1. For example, PUCCH format 1b can be used to convey a two-bit HARQ-ACK, which can be used for carrier aggregation. References to tables (e.g., mapping tables) in the 3GPP LTE Release 11 may also be found in 3GPP LTE Releases 8, 9, and 10.

Legacy LTE TDD can support asymmetric UL-DL allocations by providing seven different semi-statically configured uplink-downlink configurations. Table 2 illustrates seven UL-DL configurations used in LTE, where “D” represents a downlink subframe, “S” represents a special subframe, and “U” represents an uplink subframe. In an example, the special subframe can operate or be treated as a downlink subframe. Similar information to Table 2 can be shown in 3GPP LTE TS 36.211 Table 4.2-2.

As illustrated by Table 2. UL-DL configuration 0 can include 6 uplink subframes in subframes 2, 3, 4, 7, 8, and 9, and 4 downlink and special subframes in subframes 0, 1, 5, and 6; and UL-DL configuration 5 can include one uplink subframe in subframe 2, and 9 downlink and special subframes in subframes 0, 1, and 3-9. Each uplink subframe n can be associated with a downlink subframe based on the uplink-downlink configuration, where each uplink subframe n can have a downlink association set index Kε{k0, k1, . . . kM−1} where M is defined as the number of elements in set K, as illustrated by Table 3. Similar information to Table 3 can be shown in 3GPP LTE TS 36.213 Table 10.1.3.1-1.

The Table 3 shows examples of downlink subframe bundling in an uplink subframe handling ACK/NACK feedback for certain downlink subframe(s). For example, in uplink-downlink configuration 4, uplink subframe 2 (subframe n) handles ACK/NACK feedback for downlink and special subframes which are {12, 8, 7, 11} subframes (subframes km) earlier than uplink subframe 2 (i.e., downlink and special subframes {0, 4, 5, 1} (or downlink and special subframes n−km)) and M equals 4. Uplink subframe 3 (subframe n) handles ACK/NACK feedback for downlink subframes which are {6, 5, 4, 7} subframes (subframes km) earlier than uplink subframe 3 (i.e., downlink subframes {7, 8, 9, 6} (or downlink subframes n−km)) and M equals 4. For uplink-downlink configuration 5 uplink subframe 2, M equals 9. For uplink-downlink configuration 0, uplink subframe 2, M equals one, and uplink subframe 3, M equals zero. Depending on the uplink-downlink configuration one uplink subframe may be responsible for ACK/NACK feedback for one or multiple downlink subframes. In certain situations, even distribution between uplink subframe responsibility can be desired to reduce situations where one uplink subframe is responsible for ACK/NACK feedback for a large number of downlink and special subframes.

As an underlying requirement in some examples, cells of the network can change UL-DL (TDD) configurations synchronously in order to avoid the interference. The legacy LTE TDD set of configurations can provide DL subframe allocations in the range between 40% and 90%, as shown in Table 2. The UL and DL subframes allocation within a radio frame can be reconfigured through system information broadcast signaling (e.g., system information block [SIB]). Hence, the UL-DL allocation once configured can be expected to vary semi-statically.

A property of TDD is that a number of UL and DL subframes can be different as shown in Table 2 and often the number of DL subframes can be more than the number of UL subframes for a radio frame. In configurations where more DL subframes are used than UL subframes, multiple DL subframes can be associated with one single UL subframe for the transmission of a corresponding control signals. A configuration-specific HARQ-ACK timing relationship can be defined (e.g., 3GPP LTE standard Release 11 (e.g., V11.2.0 (2013-02)) TS 36.213 Table 10.1.3.1-1 or Table 3). If a UE is scheduled in a multiple of DL subframes, which can be associated with one UL subframe, the UE can transmit multiple ACK/NAK (ACK/NACK) bits in that UL subframe. A number of DL subframes with HARQ-ACK feedback on one single UL subframe can comprise one bundling window.

FIG. 4illustrates a PUCCH resource allocation and usage with legacy PDCCH for TDD. Only the first slot is expanded or elaborated since the second slot can have symmetry by slot-level hopping for the PUCCH. The PRBs for PUCCH format 2/2a/2b can be located from a band-edge PRB to NRB(2), which can be configured by higher layer signaling (e.g., radio resource control (RRC) signaling). If a mixed PRB for PUCCH format 2/2a/2b and PUCCH format 1/1a/1b exists, the mixed PRB can be configured by Ncs(1), where one PRB may be available for the mixed PRB. Following the mixed PRB, the PRBs for PUCCH format 1/1a/1b semi-statically configured by RRC signaling can be located. Starting from NPUCCH(1), the PRBs for PUCCH format 1a/1b by lowest CCE index based dynamic resource allocation can exist and can be located. The PUSCH can be also transmitted in the dynamic PUCCH resource region according to scheduling policies. Any PRBs can be located for PUCCH format 3 by RRC signaling. In another example the PRBs for PUCCH format 3 can be transmitted inside of bands like other PUCCH formats.

For instance, 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 can use PUCCH resource nPUCCH(1,{tilde over (p)})for transmission of HARQ-ACK in subframe n for {tilde over (p)} mapped to antenna port p for PUCCH format 1a/1b. If a PDSCH transmission is indicated by the detection of corresponding PDCCH or a PDCCH indicates a downlink semi-persistent scheduling (SPS) release within subframe(s) n−k, where kεK and K (defined in Table 3) is a set of M elements {k0, k1, . . . kM−1} depending on the subframe n and the UL-DL configuration (defined in Table 2), the UE can first select a c value out of {0, 1, 2, 3} which makes Nc≦nCCE<Nc+1and can use nPUCCH(1,{tilde over (p)}0)=(M−m−1)·Nc+m·Nc+1+nCCE+NPUCCH(1)for antenna port p0, where NPUCCH(1)is configured by higher layers (e.g., RRC signaling), Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, and nCCEis the number of the first CCE used for transmission of the corresponding PDCCH in subframe n−kmand the corresponding m, where kmis the smallest value in set K such that UE detects a PDCCH in subframe n−km. When a two antenna port transmission is configured for PUCCH format 1a/1b, the PUCCH resource for HARQ-ACK bundling for antenna port p1can be given by nPUCCH(1,{tilde over (p)}1)=(M−m−1)·Nc+m·Nc+1+nCCE+1+NPUCCH(1).

For example, for TDD, the PUCCH resources for each DL subframe can be reserved exclusively, as much as possible, and the number of reserved resources for each DL subframe can be similar to each other by applying block interleaved mapping, as illustrated inFIG. 5. By reserving the PUCCH resources for each DL subframe, PUSCH resource can be efficiently scheduled for the DL subframes within a bundling window. The PUCCH resource for HARQ-ACK in TDD can also be determined by a function of the lowest CCE index of the scheduling PDCCH.

As for EPDCCH, the subframes can be configured for monitoring EPDCCH by higher layer signaling. Therefore, within a certain bundling window, two types of downlink control channels of PDCCH and EPDCCH may coexist. For example, for a UE assuming M=4. DL subframe m=0 and 2 can be used for PDCCH while m=1 and 3 can be used for EPDCCH according to a higher layer configuration, as shown inFIG. 4. As a result, a PUCCH resource allocation method providing for the PDCCH and the EPDCCH can be defined when the bundling window uses both the PDCCH and the EPDCCH.

For example, two different types of DL control channels (i.e., PDCCH and EPDCCH) can coexist within a bundling window. A mechanism can be used to handle PUCCH resource allocation on mixed DL subframes with PDCCH and EPDCCH within a bundling window for TDD. In a configuration, the UE can follow a resource allocation method for the DL subframe derived for an actual transmitted PUCCH resource (e.g., either PDCCH or EPDCCH). In another configuration, the UE can follow a legacy PDCCH rule (e.g., base the resource allocation on the transmitted PUCCH resource (i.e., method A)). In another configuration, the UE can follow an EPDCCH rule (e.g., base the resource allocation on the transmitted EPUCCH resource (i.e., method B)).

As used herein, a bundling window for a UE where the PDCCH and the EPDCCH can coexist is referred to as “mixed bundling window,” unless otherwise stated. A method of dynamic PUCCH resource allocation in mixed bundling window for TDD is disclosed.

A dynamic PUCCH resource allocation method (e.g., method A) corresponding to legacy PDCCH (e.g., sometimes referred to as a PDCCH) can be defined for TDD. A dynamic PUCCH resource allocation method (e.g., method B) corresponding to EPDCCH can also be defined for TDD. For instance, the PUCCH resource allocation between Method A and Method B can be determined by the actually used PUCCH resource (e.g., nPUCCH(1)or nPUCCH,j(1)) derived by the DL subframe.

For example, if the actually used PUCCH resource is derived by DL subframe configured for EPDCCH, Method B may be used as the PUCCH resource allocation. If the actually PUCCH resource is derived by DL subframe not configured for EPDCCH (e.g., configured for PDCCH), Method A may be used as the PUCCH resource allocation. For example on HARQ-ACK multiplexing (i.e., PUCCH format 1b with channel selection), if a UE uses PUCCH resource nPUCCH,j(1)for transmitting HARQ-ACK feedback and the PUCCH resource is derived by m=j within a bundling window, the PUCCH resource allocation method can be applied between Method A and B based on whether the DL subframe m for PUCCH resource derivation is configured for PDCCH or configured for EPDCCH.

As for dynamic PUCCH resource allocation of TDD in a single configured cell, the PUCCH format 1a/1b transmissions and PUCCH format 1b with channel selection (i.e., HARQ-ACK multiplexing) support implicit resource allocation determined by nCCE(e.g., a lowest CCE index of the PDCCH) or nECCE(e.g., a lowest ECCE index of EPDCCH). For both PUCCH format 1a/1b and PUCCH format 1b with channel selection, the number of actual transmitted PUCCH resources may be one CCE. The used PUCCH resource can be determined either by the corresponding DL subframe or by a DL downlink assignment index (DAI) value within a bundling window. A downlink assignment index (DAI) can be a field in the downlink resource grant signaled to a wireless device (e.g., UE), indicating how many subframes in a previous time window contained transmissions to that wireless device. DAI can be applicable in time domain duplex (TDD) mode, and can enable the wireless device to determine whether wireless device has received all the downlink subframes or transport blocks for which the wireless device transmits a combined ACK/NACK.

In an example, the PUCCH resource allocation equation for TDD with EPDCCH can be represented as nPUCCH(1,{tilde over (p)}0)=nECCE+Value where nECCEcan be the lowest ECCE index number and Value can consists of various parameters. As an example. Value=ARI+AP+(m+1)·NPUCCH(1,k), where ACK/NACK Resource Indictor (ARI) is an offset value (e.g., maybe integer value) which may be given from the DCI in EPDCCH, AP is antenna port (0, . . . , 3), m is the parameter based on Table 3, and NPUCCH(1,k)is the UE specific starting offset value for EPDCCH set k. In another example, an ACK/NACK Resource Offset (ARO) can be substituted for ARI.

In a configuration, 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 can use PUCCH resource nPUCCH(1,{tilde over (p)})for transmission of HARQ-ACK in subframe n for {tilde over (p)} mapped to antenna port p for PUCCH format 1a/1b.

If there is PDSCH transmission indicated by the detection of corresponding PDCCH/EPDCCH or there is PDCCH/EPDCCH indicating downlink SPS release within subframe(s) n−k, where kεK and K (defined in Table 3) is a set of M elements {k0, k1, . . . , kM−1} depending on the subframe n and the UL-DL configuration, and if the subframe n−k, is not configured for EPDCCH, the UE can first select a c value out of {0, 1, 2, 3} which makes Nc≦nCCE<Nc+1and can use nPUCCH(1,{tilde over (p)}0)=(M−m−1)·Nc+m·Nc+1+nCCE+NPUCCH(1)for antenna port p0, where NPUCCH(1)is configured by higher layers, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, and nCCEis the number of the first CCE used for transmission of the corresponding PDCCH in subframe n−kmand the corresponding m, where kmis the smallest value in set K such that UE detects a PDCCH in subframe n−km(i.e., the last DL subframe where the PDCCH is detected within a bundling window). When two antenna port transmission is configured for PUCCH format 1a/1b, the PUCCH resource for HARQ-ACK bundling for antenna port p1can be given by nPUCCH(1,{tilde over (p)}1)=(M−m−1)·Nc+m·Nc+1+nCCE+1+NPUCCH(1).

If there is PDSCH transmission indicated by the detection of corresponding PDCCH/EPDCCH or there is PDCCH/EPDCCH indicating downlink SPS release within subframe(s) n−kmwhere kεK and K (defined in Table 3) is a set of M elements {k0, k1, . . . , kM−1} depending on the subframe n and the UL-DL configuration, and if the subframe n−kmis configured for EPDCCH, the UE can use nPUCCH(1,{tilde over (p)}0)=nECCE+Value for antenna port p0and nECCEis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−kmand the corresponding m, where kmis the smallest value in set K such that UE detects a EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km(i.e., the last DL subframe where the EPDCCH is detected within a bundling window). When two antenna port transmission is configured for PUCCH format 1a/1b, the PUCCH resource for HARQ-ACK bundling for antenna port p1can be given by nPUCCH(1,{tilde over (p)}1)=nECCE+Value+1.

If there is only a PDSCH transmission where there is not a corresponding PDCCH/EPDCCH detected within subframe(s) n−k, where kεK and K is defined in Table 3, the UE can use PUCCH format 1a/1b and PUCCH resource nPUCCH(1,{tilde over (p)})with the value of nPUCCH(1,{tilde over (p)})is determined according to higher layer configuration and Table 4 (i.e.,FIG. 6). For a UE configured for two antenna port transmission for PUCCH format 1a/1b and HARQ-ACK bundling, a PUCCH resource value in Table 4 maps to two PUCCH resources with the first PUCCH resource nPUCCH(1,{tilde over (p)}0)for antenna port p0and the second PUCCH resource nPUCCH(1,{tilde over (p)}1)for antenna port p1, otherwise, the PUCCH resource value maps to a single PUCCH resource nPUCCH(1,{tilde over (p)}0)for antenna port p0.

Therefore, for HARQ-ACK bundling or HARQ-ACK multiplexing with M=1 without carrier aggregation (CA), the PUCCH resource used can be derived from a last DL subframe within a bundling window depending on whether the DL subframe is configured by PDCCH or EPDCCH.

In another configuration, for TDD HARQ-ACK multiplexing and sub-frame 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 sub-frame n−kiand HARQ-ACK(i) as the ACK/negative ACK/discontinuous transmission (DTX) response (i.e., ACK/NACK/DTX) from sub-frame n−ki, where kεK (defined in Table 3) and 0≦i≦M−1.

For a PDSCH transmission indicated by the detection of corresponding PDCCH/EPDCCH or a PDCCH/EPDCCH indicating downlink SPS release in sub-frame n−kiwhere kiεK, and if the subframe n−kiis not configured for EPDCCH, the PUCCH resource can be represented by 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┘}, nCCE,iis the number of the first CCE used for transmission of the corresponding PDCCH in subframe n−ki, and NPUCCH(1)is configured by higher layers.

For a PDSCH transmission indicated by the detection of corresponding PDCCH/EPDCCH or a PDCCH/EPDCCH indicating downlink SPS release in sub-frame n−kiwhere kiεK, and if the subframe n−kiis configured for EPDCCH, the PUCCH resource nPUCCH,i(1)=nECCE,i+Value, nECCE,iis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−ki.

For a PDSCH transmission where there is not a corresponding PDCCH/EPDCCH detected in subframe n−ki, the value of nPUCCH,i(1)can be determined according to higher layer configuration and Table 4 (i.e.,FIG. 6).

In another configuration, 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 can transmit b(0)b(1) (e.g., constellation bits) 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 Table 6 (i.e.,FIG. 8), Table 7 (i.e.,FIG. 9), and Table 8 (i.e.,FIG. 10) 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(f and A PUCCH resources are given by Table 9 (i.e.,FIG. 11). 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 (i.e.,FIG. 12). The UE can determine the A PUCCH resources, nPUCCH,j(1)associated with HARQ-ACK(j) where 0≦j≦A−1 in Table 9 (i.e.,FIG. 11) for M=1 and Table 10 (i.e.,FIG. 12) for M=2, according to the following:

For a PDSCH transmission indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK on a primary cell, or for a PDCCH/EPDCCH indicating downlink SPS release in subframe n−km, where kmεK on the primary cell, and if the subframe n−kmis not configured for EPDCCH, the PUCCH resource can be represented by nPUCCH,j(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘} where NRBDLis determined from the primary cell, and for a subframe n with M=−1 and a transmission mode that supports up to two transport blocks on the serving cell where the corresponding PDSCH transmission occurs, the PUCCH resource nPUCCH,j+1(1)is given by nPUCCH,j+1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+1+NPUCCH(1)where nCCE,mis the number of the first CCE used for transmission of a corresponding DCI assignment and NPUCCH(1)is configured by higher layers.

For a PDSCH transmission indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK on a primary cell, or for a PDCCH/EPDCCH indicating downlink SPS release in subframe n−km, where kmεK on the primary cell, and if the subframe n−kmis configured for EPDCCH, the PUCCH resource can be represented by nPUCCH,j(1)==nECCE,m+Value and for a subframe n with M=1 and a transmission mode that supports up to two transport blocks on the serving cell where the corresponding PDSCH transmission occurs, the PUCCH resource nPUCCH,j+1(1)is given by nPUCCH,j+1(1)=nECCE,m+Value+1 where n is the number of the first CCE used for transmission of a corresponding DCI assignment by EPDCCH for the EPDCCH set {tilde over (k)}.

For a PDSCH transmission on the primary cell where there is not a corresponding PDCCH/EPDCCH detected within subframe(s) n−k, where kεK, the value of nPUCCH,j(1)can be determined according to higher layer configuration and Table 4 (i.e.,FIG. 6).

In another configuration, for TDD HARQ-ACK multiplexing with PUCCH format 1b with channel selection and sub-frame 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)as the PUCCH resource derived from the transmissions in M DL sub-frames associated with the UL subframe n, where 0≦i≦3, nPUCCH,0(1)and nPUCCH,1(1)are associated with the PDSCH transmission(s) or a PDCCH indicating downlink SPS release on the primary cell and nPUCCH,2(1)and nPUCCH,3(1)are associated with the PDSCH transmission(s) on the secondary cell.

For a primary cell, if there is a PDSCH transmission on the primary cell without a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK, the value of nPUCCH,0(1)can be determined according to higher layer configuration and Table 5 (i.e.,FIG. 7).

If there is a PDSCH transmission on the primary cell without a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK, for a PDSCH transmission on the primary cell indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to ‘1’ or a PDCCH indicating downlink SPS release in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to ‘1’, and if the subframe n−kmis not configured for EPDCCH, the PUCCH resource nPUCCH,1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1)where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, where nCCE,mis the number of the first CCE used for transmission of the corresponding PDCCH for the EPDCCH set {tilde over (k)} in subframe n−kmand NPUCCH(1)is configured by higher layers.

If there is a PDSCH transmission on the primary cell without a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k where kεK, for a PDSCH transmission on the primary cell indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to ‘1’ or a PDCCH indicating downlink SPS release in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to ‘1’, and if the subframe n−kmis configured for EPDCCH, the PUCCH resource nPUCCH,1(1)=nECCE,m+Value where nECCE,mis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km.

If there is a PDSCH transmission on the primary cell without a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK, HARQ-ACK(0) can be the ACK/NACK/DTX response for the PDSCH transmission without a corresponding PDCCH/EPDCCH. For 0≦j≦M−1, if a PDSCH transmission with a corresponding PDCCH/EPDCCH and DAI value in the PDCCH/EPDCCH equal to ‘j’ or a PDCCH/EPDCCH indicating downlink SPS release and with DAI value in the PDCCH/EPDCCH equal to ‘j’ is received. HARQ-ACK(j) can be the corresponding ACK/NACK/DTX response; otherwise HARQ-ACK(j) can be set to DTX.

Otherwise (e.g., if there is a PDSCH transmission on the primary cell with a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK), for a PDSCH transmission on the primary cell indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to either ‘1’ or ‘2’ or a PDCCH/EPDCCH indicating downlink SPS release in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to either ‘1’ or ‘2’, and if the subframe n−kmis not configured for EPDCCH, the PUCCH resource nPUCCH,i(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, where nCCE,mis the number of the first CCE used for transmission of the corresponding PDCCH in subframe n−km, NPUCCH(1)is configured by higher layers, i=0 for the corresponding PDCCH with the DAI value equal to ‘1’ and i=1 for the corresponding PDCCH with the DAI value equal to ‘2’.

Otherwise (e.g., if there is a PDSCH transmission on the primary cell with a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK), for a PDSCH transmission on the primary cell indicated by the detection of a corresponding PDCCH/EPDCCH in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to either ‘1’ or ‘2’ or a PDCCH/EPDCCH indicating downlink SPS release in subframe n−km, where kmεK with the DAI value in the PDCCH/EPDCCH equal to either ‘1’ or ‘2’, and if the subframe n−kmis configured for EPDCCH, the PUCCH resource nPUCCH,i(1)=nECCE,m+Value where nECCE,mis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)}0in subframe n−kmi=0 for the corresponding EPDCCH with the DAI value equal to ‘1’ and i=1 for the corresponding EPDCCH for the EPDCCH set {tilde over (k)}1with the DAI value equal to ‘2’.

Otherwise (e.g., if there is a PDSCH transmission on the primary cell with a corresponding PDCCH/EPDCCH detected within the subframe(s) n−k, where kεK), for 0≦j≦M−1, if a PDSCH transmission with a corresponding PDCCH/EPDCCH and DAI value in the PDCCH/EPDCCH equal to ‘j+1’ or a PDCCH/EPDCCH indicating downlink SPS release and with DAI value in the PDCCH/EPDCCH equal to ‘j+1’ is received, HARQ-ACK(j) is the corresponding ACK/NACK/DTX response: otherwise HARQ-ACK(j) can be set to DTX.

A secondary cell may not transmit an EPDCCH, so PUCCH resource allocation may use a legacy PDCCH rule for a secondary cell.

In another example, if only PDCCHs are within a bundling window, the legacy PUCCH resource allocation method can be used. If only EPDCCHs are within a bundling window, a PUCCH resource allocation method associated with EPDCCH can be used. If at least one EPDCCH is within a bundling window, either the legacy PUCCH resource allocation method can be used, or a PUCCH resource allocation associated with EPDCCH can be used, as previously described.

The same principles illustrated for the case of PUCCH format 1a/1b or PUCCH format 1b with channel selection can be applicable when PUCCH format 3 is configured (e.g., a primary cell fall-back case).

Another example provides a method500for conditional time division duplex (TDD) physical uplink control channel (PUCCH) resource allocation for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n at a user equipment (UE), as shown in the flow chart inFIG. 13. The method may be executed as instructions on a machine, computer circuitry, or a processor for the UE, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The method includes the operation of recognizing that a downlink control channel type received within a prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH), wherein the prior specified subframe occurs in time before the subframe n, as in block510. The operation of determining a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of a physical downlink control channel (PDCCH) when the downlink control channel type is the PDCCH follows, as in block520. The next operation of the method can be determining the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the downlink control channel type is the EPDCCH, as in block530.

In an example, the prior specified subframe can include a subframe n−k where kεK, and where a downlink association set index K is defined in a Table 10.1.3.1-1 in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213 (e.g., Table 3), and K can include a set of M elements {k0, k1, . . . kM−1} depending on the subframe n and an uplink/downlink (UL/DL) configuration.

In another example, the operation of determining the PUCCH resource for the subframe n−k using a lowest enhanced CCE (ECCE) index of an EPDCCH can further configured to determine the PUCCH resource using a parameter Value represent by Value=ARO+AP+(m+1)·NPUCCH(1,k), where acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO) is an integer offset value derived from a downlink control information (DCI) in the EPDCCH, an antenna port (AP) is parameter (0, . . . , 3), a NPUCCH(1,k)is a UE specific starting offset value for an EPDCCH set {tilde over (k)}, and m is an integer, where kmis the smallest value in a set K such that the UE detects an EPDCCH for an EPDCCH set {tilde over (k)} in a subframe n−km.

For one configured serving cell and the subframe n, with M=1, the operation of determining the PUCCH resource nPUCCH(1,{tilde over (p)})for the HARQ-ACK transmission using the lowest CCE index nCCEof the PDCCH can further include selecting a c value out of {0, 1, 2, 3} which makes Nc≦nCCE<Nc+1and using the PUCCH resource nPUCCH(1,{tilde over (p)})represented by nPUCCH(1,{tilde over (p)}0)==(M−m−1)·Nc+m·Nc+1+nCCE+NPUCCH(1)for antenna port p0and nPUCCH(1,{tilde over (p)}1)==(M−m−1)·Nc+m·Nc+1+nCCE+1+NPUCCH(1)for antenna port p1, where nCCEis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−kmand the corresponding m, where kmis the smallest value in set K such that UE detects a PDCCH in subframe n−km, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The antenna port p1can be used when two antenna port transmission is configured. The operation of determining the PUCCH resource nPUCCH(1,{tilde over (p)})for the HARQ-ACK transmission using the lowest ECCE index nECCEof the EPDCCH can further include using the PUCCH resource nPUCCH(1,{tilde over (p)})represented by nPUCCH(1,{tilde over (p)}0)=nECCE+Value for antenna port p0and nPUCCH(1,{tilde over (p)}1)=nECCE+Value+1 for antenna port p1, where Value is the parameter, nECCEis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−k and a corresponding m, where kmis the smallest value in set K such that UE detects an EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km. The antenna port p1can be used when two antenna port transmission is configured.

For one configured serving cell and a subframe n with M>1 where 0≦i≦M−1, the operation of determining the PUCCH resource nPUCCH,i(1)for the HARQ-ACK transmission using the lowest CCE index nCCE,iof the PDCCH can be represented by nPUCCH,i(1)=(M−m−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, nCCE,iis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−ki, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, is a downlink bandwidth configuration, expressed in units of NcsRB, NcsRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The operation of determining the PUCCH resource nPUCCH,i(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,iof the EPDCCH can be represented by nPUCCH,i(1)=nECCE,i+Value, where Value is the parameter nECCE,ithe number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−ki.

For at least two configured serving cells and a subframe n with M≦2 where kmεK on a primary cell, and 0≦j≦A−1 and Aε{2, 3, 4}, the operation of determining the PUCCH resource nPUCCH,j(1)for the HARQ-ACK transmission using the lowest CCE index nCCE,mof the PDCCH can be represented by nPUCCH,j(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1)and nPUCCH,j+1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+1+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that N≦nCCE,m<Nc+1, nCCE,mis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−ki, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration from the primary cell, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, and nPUCCH,j+1(1)is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding physical downlink shared channel (PDSCH) transmission occurs. The operation of determining the PUCCH resource nPUCCH,j(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,mof the EPDCCH can be represented by nPUCCH,j(1)==nECCE,m+Value and nPUCCH,j+1(1)=nECCE,m+Value+1, where Value is the parameter, nECCE,mis the number of the first ECCE used for transmission of the corresponding DCI assignment by EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km, and nPUCCH,j+1(1)is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding PDSCH transmission occurs.

For at least two configured serving cells and a subframe n with M>2 where kεK, kmεK for a primary cell, the operation of determining the PUCCH resource nPUCCH,1(1)for the HARQ-ACK transmission using the lowest CCE index nCCE,mof the PDCCH can be represented by nPUCCH,1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, nCCE,mis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−km, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration from the primary cell, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The operation of determining the PUCCH resource nPUCCH,1(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,mof the EPDCCH can be represented by nPUCCH,1(1)=nECCE,m+Value, where Value is the parameter, nECCE,mis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km.

Another example provides functionality600of computer circuitry of a processor on a user equipment (UE) operable to provide conditional physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n, as shown in the flow chart inFIG. 14. The functionality may be implemented as a method or the functionality may be executed as instructions on a machine, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The computer circuitry can be configured to receive a downlink control channel within a prior specified subframe, wherein the prior specified subframe occurs in time before the subframe n, as in block610. The computer circuitry can be further configured to recognize that a downlink control channel type received within the prior specified subframe is a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH), as in block620. The computer circuitry can also be configured to determine a PUCCH resource for the HARQ-ACK transmission using a lowest control channel element (CCE) index of the PDCCH when the received downlink control channel type is the PDCCH, as in block630. The computer circuitry can be further configured to determine the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of the EPDCCH when the received downlink control channel type is the EPDCCH, as in block640.

In an example, the prior specified subframe can include a subframe n−k, where kεK, and where a downlink association set index K is defined in a Table 10.1.3.1-1 in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213 (e.g., Table 3), and K can include a set of M elements {k0, k1, . . . kM−1} depending on the subframe n and an uplink/downlink (UL/DL) configuration. In another example, the subframe n−k includes a PDCCH and a configured EPDCCH subframe.

In another configuration, the computer circuitry configured to determine the PUCCH resource for the subframe n−k using the lowest ECCE index of an EPDCCH can be further configured to determine the PUCCH resource using a parameter (e.g., Value). The parameter can be derived from an acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO), an antenna port (AP), a UE specific starting offset value for an EPDCCH set, and an integer m, where a kmis the smallest value in a set K such that the UE detects an EPDCCH in a subframe n−km.

For one configured serving cell and the subframe n, with M=1 where M is a number of elements in the set Kε{k0, k1, . . . kM−1}, the computer circuitry configured to determine the PUCCH resource nPUCCH(1,{tilde over (p)})for a HARQ-ACK transmission using the lowest CCE index nCCEof the PDCCH can select a c value out of {0, 1, 2, 3} which makes Nc≦nCCE<Nc+1and uses the PUCCH resource nPUCCH(1,{tilde over (p)})represented by nPUCCH(1,{tilde over (p)}0)==(M−m−1)·Nc+m·Nc+1+nCCE+NPUCCH(1)for antenna port p0and nPUCCH(1,{tilde over (p)}1)==(M−m−1)·Nc+m·Nc+1+nCCE+1+NPUCCH(1)for antenna port p1, where nCCEis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−kmand the corresponding m, where kmis the smallest value in set K such that UE detects a PDCCH in subframe n−km, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The antenna port p1can be used when two antenna port transmission is configured. The computer circuitry configured to determine the PUCCH resource nPUCCH(1,{tilde over (p)})for the HARQ-ACK transmission using the lowest ECCE index nECCEof the EPDCCH can use the PUCCH resource nPUCCH(1,{tilde over (p)})represented by nPUCCH(1,{tilde over (p)}0)=nECCE+Value for antenna port p0and nPUCCH(1,{tilde over (p)}1)=nECCE+Value+1 for antenna port p1, where Value is the parameter, nECCEis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−kmand a corresponding m, where kmis the smallest value in set K such that UE detects an EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km. The antenna port p1can be used when two antenna port transmission is configured.

For one configured serving cell and a subframe n with M>1 where M is the number of elements in the set Kε{k0, k1, . . . kM−1} and 0≦i≦M−1, the computer circuitry configured to determine the PUCCH resource nPUCCH,i(1)for a HARQ-ACK transmission using the lowest CCE index nCCE,ican be represented by 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, nCCE,iis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−ki, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The computer circuitry configured to determine the PUCCH resource nPUCCH,i(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,ican be represented by nPUCCH,i(1)=nECCE,i+Value, where Value is the parameter, nECCE,iis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−ki.

For at least two configured serving cells and a subframe n with M≦2 where M is the number of elements in the set Kε{k0, k1, . . . kM−1}, kmεK on a primary cell, and 0≦j≦A−1 and Aε{2, 3, 4}, the computer circuitry configured to determine the PUCCH resource nPUCCH,j(1)for a HARQ-ACK transmission using the lowest CCE index nCCE,mcan be represented by nPUCCH,j(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1)and nPUCCH,j+1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+1+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, nCCE,mis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−ki, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration from the primary cell, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE, and nPUCCH,j+1(1)is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding physical downlink shared channel (PDSCH) transmission occurs. The computer circuitry configured to determine the PUCCH resource nPUCCH,j(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,mcan be represented by nPUCCH,j(1)==nECCE,m+Value and nPUCCH,j+1(1)=nECCE,m+Value+1, where Value is the parameter, nECCE,mis the number of the first ECCE used for transmission of the corresponding DCI assignment by EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km, and nPUCCH,j+1(1)is used for a subframe n and a transmission mode that support up to two transport block on a serving cell where a corresponding PDSCH transmission occurs.

For at least two configured serving cells and a subframe n with M>2 where M is the number of elements in the set Kε{k0, k1, . . . kM−1}, kεK, kmεK for a primary cell, the computer circuitry configured to determine the PUCCH resource nPUCCH,1(1)for a HARQ-ACK transmission using the lowest CCE index nCCE,mcan be represented by nPUCCH,1(1)=(M−m−1)·Nc+m·Nc+1+nCCE,m+NPUCCH(1), where c is selected from {0, 1, 2, 3} such that Nc≦nCCE,m<Nc+1, nCCE,mis a first CCE index number used for transmission of a corresponding PDCCH in subframe n−km, Nc=max{0,└[NRBDL·(NscRB·c−4)]/36┘}, NRBDLis a downlink bandwidth configuration from the primary cell, expressed in units of NscRB, NscRBis a resource block size in the frequency domain, expressed as a number of subcarriers, and NPUCCH(1)is a starting PUCCH channel index for a PUCCH region in an uplink subframe and is configured by high layers for each UE. The computer circuitry configured to determine the PUCCH resource nPUCCH,1(1)for the HARQ-ACK transmission using the lowest ECCE index nECCE,mcan be represented by nPUCCH,1(1)=nECCE,m+Value, where Value is the parameter, nECCE,mis the number of the first ECCE used for transmission of the corresponding EPDCCH for the EPDCCH set {tilde over (k)} in subframe n−km.

In another example, the computer circuitry can use the PUCCH resource nPUCCH(1,{tilde over (p)})for the HARQ-ACK transmission in a subframe n for a {tilde over (p)} mapped to an antenna port p for a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 PUCCH format 1a or 1b, or 3GPP PUCCH LTE standard Release 11 format 1b with channel selection, or 3GPP PUCCH LTE standard Release 11 format 3.

FIG. 15illustrates an example node (e.g., serving node710and cooperation node750) and an example wireless device720. The node can include a node device712and752. The node device or the node can be configured to communicate with the wireless device (e.g., UE). The node device, device at the node, or the node can be configured to communicate with other nodes via a backhaul link748(optical or wired link), such as an X2 application protocol (X2AP). The node device can include a processor714and754and a transceiver716and756. The transceiver can be configured to receive a HARQ-ACK feedback in a PUCCH resource. The transceiver716and756can be further configured to communicate with the coordination node via an X2 application protocol (X2AP). The processor can be further configured to a reverse procedure can be implemented for PUCCH detection as disclosed herein. The serving node can generate both a primary cell (PCell) and a secondary cell (SCell). The node (e.g., serving node710and cooperation node750) can include a base station (BS), a Node B (NB), an evolved Node B (eNB), a baseband unit (BBU), a remote radio head (RRH), a remote radio equipment (RRE), a remote radio unit (RRU), or a central processing module (CPM).

The device (used by a node) can be configured to detect a physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe n. The transceiver716and756can be configured to receive a PUCCH resource in a subframe n configured with a downlink control channel type. The processor714and754can be configured to: Determine when the subframe it is configured with a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (EPDCCH); decode the PUCCH resource for a HARQ-ACK transmission using a lowest control channel element (CCE) index of a physical downlink control channel (PDCCH) when the downlink control channel type is the PDCCH; and decode the PUCCH resource for the HARQ-ACK transmission using a lowest enhanced CCE (ECCE) index of an EPDCCH when the downlink control channel type is the EPDCCH.

In an example, the downlink control channel type can be received in a subframe n−k, where kεK, where a downlink association set index K is defined in a Table 10.1.3.1-1 (e.g., Table 3) in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard Release 11 Technical Specification (TS) 36.213, and K includes a set of M elements {k0, k1, . . . kM−1} depending on the subframe n and a uplink/downlink (UL/DL) configuration.

In another example, the processor configured to decode the PUCCH resource for the HARQ-ACK transmission using the lowest ECCE index of the EPDCCH can be further configured to decode the PUCCH resource using a parameter Value represent by Value=ARO+AP+(m+1)·N·NPUCCH(1,k)where acknowledgement (ACK)/negative ACK (ACK/NACK) Resource Offset (ARO) is an integer offset value derived from a downlink control information (DCI) in the EPDCCH, an antenna port (AP) is parameter (0, . . . , 3), a N·NPUCCH(1,k)is a UE specific starting offset value for an EPDCCH set {tilde over (k)}, and m is an integer, where kmis the smallest value in a set K such that the UE detects an EPDCCH for an EPDCCH set {tilde over (k)} in subframe n−km.

The wireless device720(e.g., UE) can include a transceiver724and a processor722. The wireless device (i.e., device) can be configured provide conditional physical uplink control channel (PUCCH) resource allocation in time division duplex (TDD) for a hybrid automatic retransmission re-quest-acknowledge (HARQ-ACK) transmission in a subframe it, as described in500ofFIG. 13 or 600ofFIG. 14.

FIG. 16also provides an illustration of a microphone and one or more speakers that can be used for audio input and output from the wireless device. The display screen may be a liquid crystal display (LCD) screen, or other type of display screen such as an organic light emitting diode (OLED) display. The display screen can be configured as a touch screen. The touch screen may use capacitive, resistive, or another type of touch screen technology. An application processor and a graphics processor can be coupled to internal memory to provide processing and display capabilities. A non-volatile memory port can also be used to provide data input/output options to a user. The non-volatile memory port may also be used to expand the memory capabilities of the wireless device. A keyboard may be integrated with the wireless device or wirelessly connected to the wireless device to provide additional user input. A virtual keyboard may also be provided using the touch screen.