Patent Description:
The 5th generation New Radio (<NUM> NR) wireless communication network is the proposed next generation wireless communication network for which telecommunications standards are currently being developed. The <NUM> NR network will be an end-to-end ecosystem to enable a fully mobile and connected society. The Next Generation Mobile Networks Alliance estimates that <NUM> NR networks will be rolled out by <NUM> to meet business and consumer demands. In addition to providing faster speeds, it is predicted that <NUM> NR networks also will need to meet new use cases, such as the Internet of Things (internet connected devices), as well as broadcast-like services and lifeline communication in times of natural disaster. Carriers, chipmakers, original equipment manufacturers (OEMS) and out-sourced assembly and test companies (OSATs), have been preparing for this next-generation (<NUM>) wireless standard, as mobile systems and base stations will require new and faster application processors, basebands and RF devices. Although updated standards that define capabilities beyond those defined in the current <NUM> standards are under consideration, those new capabilities have been grouped under the current ITU-T <NUM> standards.

To support increasingly growing demands on enhanced mobility bandwidth, higher reliability, lower transmission delay, and mass number of connections, it is desirable to increase the reliability of various data transmissions under the constraint of a range of delay requirements. A simple method is to increase the reliability of each transmission to a same level. To maintain system spectrum efficiency, however, different reliability requirements, i.e., different target Block Error Ratios (BLER), should be applied to initial data transmissions or retransmissions during Hybrid Automatic Repeat Request (HARQ) processes. Reporting Channel Quality Indicator (CQI) index values corresponding to different target levels may be implemented to meet this goal; however, the problem is that the overheads would be high and delay may be too long. Another method is to represent different levels of error by feeding back different levels of negative acknowledgement (NACK) signals for data transmission, where retransmission may choose different rates of transmission to meet different reliability requirements corresponding to different levels of NACK.

To date, however, no research has been conducted regarding allocating different resources for transmission of uplink signals for different levels of NACK. In addition, for Physical Uplink Control Channel (PUCCH) signals based on sequence resources, no research has been conducted regarding how to allocate resources for carrying scheduling requests (SR). Thus, there is a need for a method and system for allocating channel resources efficiently to meet the anticipated demands of the <NUM> NR wireless communication network. <NPL>) relates to short PUCCH designs in NR. <CIT> is a document under Article <NUM>(<NUM>) EPC and relates to a user equipment (UE) including processing circuitry configured to decode physical uplink control channel (PUCCH) configuration information received from a Next Generation Node-B (gNB). <NPL>, relates to SR for URLLC and multiplexing with HARQ-ACK.

Preferred embodiments are recited in the dependent claims. The exemplary embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, devices and computer program products are disclosed herein.

Various exemplary embodiments of the invention are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the invention.

<FIG> illustrates an exemplary wireless communication network <NUM> in which techniques disclosed herein may be implemented, in accordance with various embodiments of the present disclosure. The exemplary communication network <NUM> includes a base station (BS) <NUM> and a user equipment (UE) device <NUM> that can communicate with each other via a communication link <NUM> (e.g., a wireless communication channel), and a cluster of notional cells <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> overlaying a geographical area <NUM>. In <FIG>, the BS <NUM> and UE <NUM> are contained within the geographic boundary of cell <NUM>. For example, the base station <NUM> may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE <NUM>. The base station <NUM> and the UE <NUM> may communicate via a downlink radio frame <NUM>, and an uplink radio frame <NUM> respectively. In the present disclosure, the base station (BS) <NUM> and user equipment (UE) <NUM> are described herein as non-limiting examples of "communication devices," generally, which can practice the methods disclosed herein. Such communication devices may be capable of wireless and/or wired communications, in accordance with various embodiments of the invention.

<FIG> illustrates a block diagram of an exemplary wireless communication system <NUM> for transmitting and receiving wireless communication signals, e.g., OFDM/OFDMA signals, in accordance with some embodiments of the invention. The system <NUM> may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one exemplary embodiment, system <NUM> can be used to transmit and receive data symbols in a wireless communication environment such as the wireless communication environment <NUM> of <FIG>, as described above.

System <NUM> generally includes a base station <NUM> and a UE <NUM>. The base station <NUM> includes a BS transceiver module <NUM>, a BS antenna <NUM>, a BS processor module <NUM>, a BS memory module <NUM>, and a network communication module <NUM>, each module being coupled and interconnected with one another as necessary via a data communication bus <NUM>. The UE <NUM> includes a UE transceiver module <NUM>, a UE antenna <NUM>, a UE memory module <NUM>, and a UE processor module <NUM>, each module being coupled and interconnected with one another as necessary via a date communication bus <NUM>. The BS <NUM> communicates with the UE <NUM> via a communication channel <NUM>, which can be any wireless channel or other medium known in the art suitable for transmission of data as described herein.

In accordance with some embodiments, UE transceiver <NUM> may be referred to herein as an "uplink" transceiver <NUM> that includes a RF transmitter and receiver circuitry that are each coupled to the antenna <NUM>. Similarly, in accordance with some embodiments, the BS transceiver <NUM> may be referred to herein as a "downlink" transceiver <NUM> that includes RF transmitter and receiver circuity that are each coupled to the antenna <NUM>. A downlink duplex switch (not shown) may alternatively couple the downlink transmitter or receiver to the downlink antenna <NUM> in time duplex fashion. The operations of the two transceivers <NUM> and <NUM> are coordinated in time such that the uplink receiver is coupled to the uplink antenna <NUM> for reception of transmissions over the wireless transmission link <NUM> at the same time that the downlink transmitter is coupled to the downlink antenna <NUM>. Preferably there is close time synchronization with only a minimal guard time between changes in duplex direction.

In some exemplary embodiments, the UE transceiver <NUM> and the base station transceiver <NUM> are configured to support industry standards such as the Long Term Evolution (LTE) and emerging <NUM> standards, and the like. It is understood, however, that the invention is not necessarily limited in application to a particular standard and associated protocols.

The network communication module <NUM> generally represents the hardware, software, firmware, processing logic, and/or other components of the base station <NUM> that enable bidirectional communication between base station transceiver <NUM> and other network components and communication devices configured to communication with the base station <NUM>.

Referring again to <FIG>, as discussed above, when the BS <NUM> is preparing to transmit and receive data from the UE <NUM>, a channel estimation process is typically performed before the BS actually transmits and receives the data from the UE <NUM>. During such a channel estimation process, one or more reference signals are typically transmitted from the BS <NUM> to the UE <NUM> via one or more physical channels.

In accordance with some embodiments, the BS <NUM> may configure the UE <NUM> with a PUCCH resource that supports multiple levels of NACK, where the number of all levels of multi-level NACKs are equal to N and N is an integer larger than <NUM>. For example, where N=<NUM>, the multi-level NACK has three levels, NACK1, NACK2, and NACK3. The following description is for the example where N=<NUM>, but the invention is not so limited.

In accordance with various embodiments, each different NACK level can be associated with at least one of the following: a CQI offset value, a CQI index value, a target BLER level, a rate offset value, a rate value, a signal to interference plus noise ratio (SINR) level, and a SINR offset value. For example, if each different NACK level is associated with a predetermined CQI offset value, the UE <NUM> may correlate a detected SINR value to a needed or desired rate, e.g., a rate associated with the CQI index corresponding to NACK1. The UE may also compute a CQI offset according to a delay requirement of a particular application or communication session. For the example of N=<NUM>, CQI offsets of [<NUM>, -<NUM>, -<NUM>] can represent no offset, a moderate offset, and a maximum offset, respectively. The actual CQI is the CQI reported by UE plus the CQI offset corresponding to the various NACK levels.

In accordance with some embodiments, a NACK level may be determined at least partially based on a number of retransmission opportunities remaining from a predetermined number of retransmission tries. For example, if there is only one retransmission opportunity remaining, the CQI index corresponding to the lowest target BLER with the maximum offset is used. In that case, UE <NUM> will transmit NACK3 on an uplink resource corresponding to NACK3 as identified by the BS <NUM>. If there are two retransmission opportunities remaining, the CQI corresponding to the moderate target BLER with the moderate offset is used. In that case, UE will transmit NACK2 on the resource corresponding to NACK2 as identified by the BS <NUM>. For example, if the CQI index most recently reported by the UE <NUM> is <NUM> and the NACK level is a NACK2 level, then the CQI index is updated to <NUM> - <NUM> = <NUM>, which corresponds to a modulation and coding scheme (MCS) having a lower data rate for the retransmission, which corresponds to a lower BLER for retransmission, when compared to NACK <NUM> MCS and BLER. As another example, if the CQI index most recently reported by the UE <NUM> is <NUM> and the NACK level is a NACK3 level, then the CQI index is updated to <NUM> - <NUM> = <NUM>, which corresponds to a modulation and coding scheme (MCS) having an even lower data rate for the retransmission, which corresponds to an even lower BLER for retransmission, when compared to the NACK2 MCS and BLER.

In some embodiments, the resources for the multi-level NACKs are determined by different sequence resources. The BS <NUM> may allocate to the UE <NUM> one sequence to represent an ACK resource and N sequences to provide N different NACK resources for transmitting N different levels of NACK. For N=<NUM>, the UE <NUM> is allocated a total number of <NUM>+<NUM>=<NUM> sequence resources for transmitting ACK, NACK1, NACK2 and NACK3 signals.

For the example of sequences generated by a computer (i.e., computer generated sequences (CGS)), in accordance with some embodiments, the base sequences can be r(n) = ejφ(n)π/<NUM>, where <NUM> ≤ n ≤ M and the length of the sequences is <NUM> (i.e., M=<NUM>). φ(n) is an element from the set [<NUM>, -<NUM>, <NUM>, -<NUM>]. The ACK, NACK1, NACK2, and NACK3 sequences can be obtained by different cyclic shifts of base sequences by α, in accordance with the following equation: rα(n) = ejαnr(n). The sequence is not limited to a CGS, and may also be a Zadoff-Chu (ZC) sequence, for example, or other sequences. Further, the length of the sequence is not limited to <NUM>, and may be other values, such as <NUM> or <NUM>.

For the PUCCH based on a sequence, in some embodiments, four PUCCH sequence resources are allocated in the same time domain when allocating PUCCH resources. A same time domain may be a same slot, a same mini-slot, a same symbol, or the same group of symbols, for example.

In some embodiments, the four sequence resources may be in the same frequency domain resource. In other embodiments, the four sequence resources may be in different frequency domain resources. When allocated in different frequency domain resources, the resources represent different HARQ-ACK statuses and may be allocated evenly or unevenly, as described in further detail below.

In one embodiment, the resources are allocated in a same frequency domain resource by allocating the sequence resources in a first physical resource block (PRB). In some embodiments, the resources may be sequence resources derived by cyclic shift the same base sequence by four different units to provide sequence resources for ACK, NACK1, NACK2 and NACK3 transmission.

In another embodiment, the resources are allocated in different frequency domain resources and allocated evenly. For example, two resources (e.g., two sequence resources) are generated by cyclic shifting a base sequence by two different cyclic shifts to represent ACK and NACK1, and allocated to a first PRB. Two more resources (e.g., two sequence resources) are generated by cyclic shifting a base sequence by two different cyclic shifts to represent NACK2 and NACK3, and are allocated to a second PRB. In accordance with various embodiments, respective ones of the sequence resources allocated in different PRBs can be identical to each other, completely different, or partially the same (i.e., having some but not all matching sequence values).

<FIG> illustrates an example of an initial transmission of a signal transmitted by the BS <NUM> to the UE <NUM> in a physical downlink shared channel (PDSCH) resource <NUM> during a first transmission time interval (TTI) <NUM>, in accordance with some embodiments. Depending on whether the initial transmission is successfully received by the UD <NUM>, the UE <NUM> will send back one of four possible HARQ-ACK messages, e.g., ACK, NACK1, NACK2 and NACK3, each message being allocated to a different resource for transmission of the HARQ-ACK message, in accordance with some embodiments. After receiving the initial transmission, the UE <NUM> will transmit acknowledgement information (e.g., a HARQ-ACK message), in this case a CQI index offset value corresponding to a NACK1 level, using a resource <NUM> (e.g., PRB #n1 in a OFDM symbol (OS) <NUM>) allocated for NACK1 during a second TTI <NUM>. Next, in response to the CQI index offset value transmitted in OS <NUM>, the BS <NUM> will retransmit the same signal in a PDSCH resource <NUM> during a third TTI <NUM>. Note, the timing for initial transmission and its HARQ-ACK feedback in the embodiment is <NUM> TTI, which is just an example. In other embodiments, the timing can be other values. This is also true with respect to the timings for HARQ-ACK messages and retransmissions.

As shown in <FIG>, each of the above transmissions are performed using resources having a frequency-domain component (vertical access represented by "F") and a time-domain component (horizontal access designated by "T") such as a physical resource block (PRB), for example. As discussed above, a modulation and coding scheme (MCS) and the resources allocated to the retransmission can depend on the level of the NACK. In some embodiments, a NACK1 level corresponds to no CQI offset. Therefore, the MCS and resources allocated to the retransmission will correspond to the CQI index value reported by the UE <NUM> to BS <NUM> without any adjustments (i.e., without CQI offset). In some embodiments, the resources corresponding to NACK1 are allocated as one or more OFDM symbols (OS) <NUM> and, as shown in <FIG>, the NACK <NUM> retransmission resources <NUM> can be the same (e.g., same frequency and/or time domain resources) as the initial transmission resources <NUM>. In some embodiments, there are <NUM> resource elements (REs) in one OFDM symbol (OS) contained in one physical resource block (PRB). A sequence having a length of <NUM> can represent one HARQ-ACK message and is mapped onto the <NUM> REs in the PRB in one OFDM symbol as configured by the BS <NUM>.

<FIG> illustrates a scenario, wherein a NACK3 is sent back on a resource <NUM> allocated for NACK3 during the second TTI <NUM>. As indicated in <FIG>, the resource <NUM> is different (e.g., different frequency-domain) from the resource <NUM> allocated for NACK1, as shown in <FIG>. As further shown in <FIG>, when a NACK3 is received by the BS <NUM>, the BS <NUM> will apply a corresponding CQI index offset to a CQI index value received by the BS <NUM> from the UE <NUM>. For example, if the CQI offset for NACK3 is -<NUM>, the CQI index reported by the UE <NUM> will be decreased by <NUM> and corresponding MCS, BLER and resources will be allocated for retransmission. In accordance with some embodiments, a NACK3 level indicates that retransmission should be made with a more robust set of resources and/or at a lower data rate, corresponding to lower BLER values. In <FIG>, the retransmission resource <NUM> corresponds to a NACK3 level retransmission resource, and is allocated based on the MCS, BLER and other criteria corresponding the CQI index with an offset specified by a NACK3 level NACK. In some embodiments, as indicated in <FIG>, the retransmission resource <NUM> includes additional subcarriers compared to a NACK2 retransmission resource, which includes more subcarriers than a NACK1 retransmission resource. As shown in <FIG>, the MCS and the corresponding resources <NUM> determined for retransmission in accordance with the CQI index value plus the corresponding CQI offset for a NACK3 resource in a second PRB (PRB #n2).

In some embodiments, the resources are allocated in different frequency domain resources and allocated unevenly. For example, one resource (i.e., one sequence resource) is allocated in PRB #n1 contained in one OFDM symbol, and generated, for example, by cyclic shifting based on a base sequence, and represents ACK. Three resources (e.g., sequence resources) are allocated in PRB #n2 contained in the same OFDM symbol, and generated, for example, by cyclic shifting by three cyclic shifts based on a same base sequence, and represent NACK1, NACK2 and NACK3, respectively. The sequences resources allocated in different PRBs can be completely the same, completely different, or partially the same, in accordance with various embodiments.

In some embodiments, multiple levels of NACK (e.g., NACK1, NACK2 and NACK3) are transmitted using different sequence resources during uplink communication from the UE <NUM> to the BS <NUM>. By doing so, data retransmission will accommodate different levels of reliability requirements and improve system spectrum efficiency while maintaining low delay and high reliability transmission.

In some embodiments, a base station may configure a terminal with a PUCCH resource that supports multi levels of NACK, where the number of all levels of multi-level NACKs are equal to N and N is an integer larger than <NUM>. For example, where N=<NUM>, the multi-level NACK has three levels, NACK1, NACK2, and NACK3. The following description is for the example where N=<NUM>, but the invention is not so limited.

Different levels of NACK may correspond to different parameter values as discussed above. For example, each different NACK level may be associated with one or more of the following parameter values: a CQI offset, a CQI index, a target BLER level, a rate offset, a rate value, a signal to interference plus noise ratio (SINR) level, and a SINR offset.

The resources for the multi-level NACKs are determined by difference sequence resources. A base station may allocate a UE one sequence to represent an ACK resource and N sequences to represent N NACK resources for N levels of NACK. For N=<NUM>, a UE is allocated a total number of <NUM>+<NUM>=<NUM> sequences, i.e., one sequence for each of ACK, NACK1, NACK2, and NACK3, respectively.

In some embodiments, for the PUCCH based on a sequence, four PUCCH resources are allocated in different time domains when allocating PUCCH resources for multi-level NACKs. The different time domains may be different slots, different mini-slots, different symbols, or different several symbols. Moreover, the four PUCCH resources may be in different time domain resources, representing different HARQ-ACK messages (e.g., ACK, NACK1, , NACK2 or NACK3), whether allocated evenly or unevenly, as described in further detail below.

In one embodiment, the resources are allocated in different time domain resources and allocated evenly. For example, two resources (i.e., two sequence resources) are allocated in a first OFDM Symbol (OS) #n1, and generated, for example, by cyclic shifting by two different units based on a same base sequence, and represent ACK and NACK1, respectively. Two further resources (i.e., two sequence resources) are allocated to a second OS #n2, and generated, for example, by cyclic shifting by two different units the same base sequence, and represent NACK2 and NACK3, respectively. The sequence resources allocated in different OS's can be completely the same, completely different, or partially the same. Additionally, the frequency domain resources (e.g., PRB positions) of the sequence resources allocated in different OS's can be completely the same, completely different, or partially the same.

In some embodiments, the resource for a worst level of NACK (e.g., NACK3) appears at a symbol location that is earlier in time domain. In this way, the worst level of NACK can be transmitted earlier to allow the BS (e.g., an eNB) to retransmit a signal as soon as possible when the retransmission timing is not fixed. As shown in <FIG>, a signal is initially transmitted from the BS <NUM> to the UE <NUM> using an allocated PDSCH resource <NUM> as an initial transmission resource <NUM>. Depending on whether the signal is successfully or unsuccessfully received (e.g., decoded successfully or unsuccessfully), the UE <NUM> will send back either an ACK message if the signal was successfully received, or one of multiple possible NACK messages (e.g., NACK1, NACK2, NACK3) depending the level of errors (e.g., BLER) and/or number of retransmission attempts remaining, for example. In accordance with some embodiments, the greater the level of error and/or smaller the number of retransmission attempts, the higher the NACK level, which corresponds to more robust retransmission schemes and/or retransmission resources. For example, a NACK3 may correspond to a lower data rate (hence lower error rate) and/or more frequency and/or time-domain resources being allocated for retransmission.

Returning to <FIG>, in response to receiving the initial transmission or detecting the attempted initial transmission, the UE <NUM> sends a transmission acknowledgement message (e.g., a HARQ-ACK message) using a resource <NUM> (e.g., OS <NUM>) allocated to the corresponding type of transmission acknowledgement message. In the example of <FIG>, the OS <NUM> may contain a NACK3 level NACK and correspond to a first OS #n1, which is advanced in the time domain by a predetermined amount, as discussed above. Therefore, a corresponding MCS and the corresponding resources <NUM> for a NACK3 will be determined for retransmission with a CQI offset corresponding to NACK3. As shown in <FIG>, the retransmission parameters (e.g., MCS, BLER, etc.) and resources <NUM> corresponding to NACK3 may be more robust compared to those of NACK2 and NACK1, respectively.

<FIG> illustrates an exemplary scenario, wherein a NACK1 is transmitted back by the UE <NUM> on an allocated uplink resource <NUM> (e.g., an OS <NUM>) corresponding to NACK1. As shown in <FIG>, the resource <NUM> is delayed in time compared to the resource <NUM> for NACK3 discussed above, and is therefore handled with less urgency than NACK3 level NACKs. As further shown in <FIG>, the MCS and the corresponding resources determined for retransmission without CQI offset is determined according to the NACK1 in OS <NUM>.

In some embodiments, the resources for transmitting acknowledgement information are allocated in different time domain resources and allocated unevenly. For example, one resource (i.e., one sequence resource) is allocated in a first OS #n1, and generated, for example, by cyclic shifting a base sequence to represent NACK3. Three resources (i.e., three sequence resources) are allocated in a second OS #n2, and generated, for example, by cyclic shifting the same base sequence by three different units, to represent ACK, NACK1 and NACK2, respectively. The sequence resources allocated in different OS's can be completely the same, completely different, or partially the same, in accordance with various embodiments. Furthermore, the frequency domain resources (e.g., PRB positions) of the sequence resources allocated in different OS's can be completely the same, completely different, or partially the same, in accordance with various embodiments.

The uplink information transmission methods discussed above, in accordance with some embodiments, may implement transmitting multi-level NACK on different sequence resources, where a worse level NACK may be transmitted earlier. By doing so, data retransmission will accommodate different levels of reliability requirements and improve system spectrum efficiency while maintaining low delay and high reliability transmission.

In some embodiments, base station may configure a terminal with a PUCCH resource that supports multi levels of NACK, where the number of all levels of multi-level NACKs are equal to N and N is an integer larger than <NUM>. For example, where N=<NUM>, the multi-level NACK has three levels, NACK1, NACK2, and NACK3. The following description is for the example where N=<NUM>, but the invention is not so limited.

In some embodiments, each level of a multi-level NACK can be associated with one or more of the following parameters: a CQI offset, a CQI index, a target BLER level, a rate offset, a rate value, a signal to interference plus noise ratio (SINR) level, and a SINR offset.

The resources for the multi-level NACKs are determined by difference sequence resources, in accordance with some embodiments. A base station may allocate a UE one sequence to represent an ACK resource and N sequences to represent N NACK resources for N levels of NACK. For N=<NUM>, a UE is allocated a total number of <NUM>+<NUM>=<NUM> sequences, i.e., ACK, NACK <NUM>, NACK2, and NACK3.

In one embodiment, for PUCCH signals based on a DeModulation Reference Signal (DMRS), when allocating PUCCH resources, two PUCCH resources are allocated in the same time domain. A same time domain may be a same slot, a same mini-slot, a same symbol, or a same set of multiple symbols. Moreover, the two resources may be in the same frequency domain resource or different frequency domain resources, in accordance with various embodiments. When allocated in different frequency domain resources, the resources represent different HARQ-ACK statuses (e.g., ACK, NACK1, NACK2 or NACK3), allocated evenly, as described in further detail below.

In one embodiment, the resources are allocated in the same frequency domain resource by allocating two resources in PRB #n1, e.g., two sequence resources generated by cyclic shifting based on a same base sequence by <NUM> different units, where one of the sequences is multiplied by a BPSK modulated symbol and represents ACK and NACK1, and the other sequence is also multiplied by a BPSK modulated symbol and represents NACK2 and NACK3.

In another embodiment, the resources are allocated in different frequency domain resources and allocated evenly. For example, one resource (i.e., one sequence resource) is allocated in PRB #n1, and generated, for example, by cyclic shifting a base sequence, where the sequence is multiplied by a BPSK modulated symbol and represents ACK and NACK1. One resource (i.e., one sequence resource) is allocated in PRB #n2, and generated, for example, by cyclic shifting a base sequence, where the sequence is multiplied by a BPSK modulated symbol and represents NACK2 and NACK3. The sequence resources allocated in different PRBs can be completely the same, completely different, or partially the same. Referring again to <FIG>, an MCS and the corresponding resources determined for retransmission without CQI offset is determined according to the NACK1 in PRB #n1, as discussed above. As shown in <FIG>, an MCS and the corresponding resources determined for retransmission with a CQI offset is determined according to the NACK3, for example, in PRB #n2. A similar scenario to that illustrated in <FIG> can be depicted for retransmission with a CQI offset determined according to a NACK2 HARQ-ACK message transmitted by the UE <NUM> to the BS <NUM>, for example.

In some embodiments, for PUCCH signals based on a DeModulation Reference Signal (DMRS), when allocating PUCCH resources, one PUCCH resource is allocated in the same time domain. A same time domain may be a same slot, a same mini-slot, a same symbol, or same set of multiple symbols. One resource (i.e., one sequence resource) is allocated in PRB #n1, and generated, for example, by cyclic shifting a base sequence, where the sequence is multiplied by a QPSK modulated symbol and represents ACK, NACK1, NACK2, and NACK3, respectively.

In one embodiment, for the PUCCH based on a sequence, two PUCCH resources are allocated in different time domains when allocating PUCCH resources. The different time domains may be different slots, different mini-slots, different symbols, or different group symbols. Moreover, the two PUCCH resources may be in different time domain resources, representing different HARQ-ACK statuses and allocated evenly, as described in further detail below.

In one embodiment, the resources are allocated in different time domain resources and allocated evenly. For example, one resource (i.e., one sequence resource) is allocated in OFDM Symbol (OS) #n1, and generated, for example, by cyclic shifting a base sequence, where the sequence is multiplied by a BPSK modulated symbol and represents ACK and NACK1. Another resource (i.e., one sequence resource) is allocated in OS #n2, and generated, for example, by cyclic shifting a base sequence, where the sequence is multiplied by a BPSK modulated symbol and represents NACK2 and NACK3. The sequence resources allocated in different OS's can be completely the same, completely different, or partially the same, in accordance with various embodiments. The frequency domain resources (e.g., PRB positions) of the sequence resources allocated in different OS's can be completely the same, completely different, or partially the same, in accordance with various embodiments. Preferably, the resource for a worse level of NACK (e.g., NACK3) appears at a symbol location that is earlier in time domain, as shown in <FIG>, for example. Referring again to <FIG>, in the above described scenarios, when the HARQ-ACK message is a NACK3, an MCS and the corresponding resources determined for retransmission with CQI offset is determined according to the NACK3 in OS #n1, as shown in <FIG>. Similarly, as shown in <FIG>, when the HARQ-ACK message is a NACK3, an MCS and the corresponding resources determined for retransmission without CQI offset is determined according to the NACK1 in OS #n2.

As discussed above, in various embodiments, uplink information transmission methods may implement transmission of multi-level NACKs on different resources. By doing so, data retransmission will accommodate different levels of reliability requirements and improve system spectrum efficiency while maintaining low delay and high reliability transmission.

In some embodiments, a base station may configure a terminal with a PUCCH resource configured to carry a scheduling request (SR), where a plurality of resources (e.g., <NUM>) may be allocated for carrying the SR. A partial status saving can be supported by transmitting the SR with HARQ-ACK message simultaneously, in accordance with various embodiments. In some embodiments, the resources can be determined by different sequences within the same frequency domain resource. As discussed above, in some embodiments, the sequence resources can be derived by different cyclic shifting based on a base sequence.

In one embodiment, a base station configures one resource as an SR resource, which can be used when an SR is transmitted and a HARQ-ACK message is not transmitted. In some embodiments, when the SR and the HARQ-ACK need to be transmitted simultaneously but the simultaneous transmission is not supported, only the HARQ-ACK information is transmitted and the SR transmission is abandoned. When the SR and the HARQ-ACK need to be transmitted simultaneously and simultaneous transmission is supported by the UE, for example, transmission is performed within the configured HARQ-ACK and SR resources, where different meanings are represented by different resources. When the HARQ-ACK message is only <NUM> bit, for example, two resources are allocated for HARQ-ACK to represent ACK and NACK, respectively. Here, with the SR resource, there are three resources in total, by which the information of simultaneous transmission is represented, as shown in Table <NUM> below. Here, the three resources represent transmitting ACK only, transmitting NACK only, and transmitting ACK and SR simultaneously, respectively. When transmitting simultaneously, SR has only one resource and may only represent one status. Since the probability of ACK is higher, the SR resource may be used to represent ACK. When transmitting NACK and SR simultaneously, the resource for NACK is still used, meaning SR is dropped (e.g., with <NUM>% of probability since probability of a NACK is <NUM>%). Then the UE will transmit in a next available transmission period. Alternatively, when NACK and SR are transmitted simultaneously, both NACK resource and SR resource are used for transmission (i.e., UE sends two sequences simultaneously).

Alternatively, as shown in Table <NUM> below, when NACK and SR are transmitted simultaneously, SR has only one resource and represent only one status. Thus, to avoid missing a PDCCH detection that leads to inconsistent understanding between the base station and UE, the SR resource may be used to represent NACK. When ACK and SR are transmitted simultaneously, the ACK resource is used. In this scenario, SR is deemed to be dropped (with <NUM>% of probability), and the UE will transmit in a next available transmission period.

In some embodiments, a base station can configures two resources as an SR resource. When a SR is transmitted and a HARQ-ACK message is not, one of the two resources is used to transmit SR, where the two resources either correspond to different traffic types, respectively, e.g., eMBB and URLLC traffic, or correspond to different lengths of TTI, e.g., sTTI and TTI. When the SR and the HARQ-ACK need to be transmitted simultaneously but the simultaneous transmission is not supported, only the HARQ-ACK information is transmitted and the SR transmission is abandoned. When the SR and the HARQ-ACK need to be transmitted simultaneously and the simultaneous transmission is supported, transmission is performed within the configured HARQ-ACK and SR resources, where different meanings are represented. When the HARQ-ACK message is <NUM> bit, two resources are allocated for HARQ-ACK to represent ACK and NACK, respectively. In this case, there are four resources in total, representing transmitting ACK only, transmitting NACK only, transmitting ACK and SR simultaneously, and transmitting NACK and SR simultaneously, respectively. As shown in Table <NUM> below, the same resource is used when the SR is transmitted using one of the two resources and when NACK and SR are transmitted simultaneously.

In some embodiments, the HARQ-ACK message can be <NUM> bits, and four resources are allocated for the HARQ-ACK messages to represent {ACK, ACK}, {NACK, ACK}, {ACK, NACK}, and {NACK, NACK}, respectively. Here, with the SR resource, there are six resources in total, representing transmitting {ACK, ACK} only, transmitting {NACK, ACK} only, transmitting {ACK, NACK} only, transmitting {NACK, NACK}, transmitting {ACK, ACK} and SR simultaneously, transmitting {NACK, ACK} and SR simultaneously, as shown in Table <NUM> below. Thus, it is about <NUM>% probability that the current SR will be dropped; however, this will not lead to unnecessary retransmission of transport block.

In some embodiments, to avoid missing a PDCCH detection that leads to an inconsistent understanding between the base station and UE, with the SR resource, there are six resources in total represent transmitting {ACK,ACK} only, transmitting {NACK,ACK} only, transmitting {ACK,NACK} only, transmitting {NACK,NACK} only, transmitting {NACK,NACK} and SR simultaneously, and transmitting {NACK,ACK} and SR simultaneously, as shown in Table <NUM> below.

In accordance with some embodiments, another method is to use <NUM> bits and the simultaneous transmission of ACK/NACK and SR is implemented in a bundling way, as shown in Table <NUM> below. Two SR resources may be allocated for "SR only" transmission and may differentiate different traffic types; however, when transmitted simultaneously with ACK/NACK, different traffic types may not be differentiated.

In some embodiments, a base station configures three resources as SR resources. When an SR is transmitted and HARQ-ACK message is not, SR is transmitted on one of the three resources, where the other two resources of the three resources either correspond to different traffic types, respectively, e.g., eMBB and URLLC traffic, or correspond to different lengths of TTI, e.g., sTTI and TTI, or where the three resources correspond to different traffic types, respectively, e.g., eMBB, mMTC, and URLLC traffic, or correspond to different lengths of TTI, e.g., sTTI_2OS, sTTI_7OS, and TTI. When the SR and the HARQ-ACK need to be transmitted simultaneously but simultaneous transmission is not supported, only the HARQ-ACK information is transmitted and the SR transmission is abandoned. When the SR and the HARQ-ACK message needs to be transmitted simultaneously and simultaneous transmission is supported, transmission is performed within the configured HARQ-ACK and SR resources, where different meanings are represented. When the HARQ-ACK message is <NUM> bits, four resources are allocated for HARQ-ACK messages to represent {ACK, ACK}, {NACK, ACK}, {ACK, NACK}, and {NACK, NACK}. Here, there are seven resources in total, representing transmitting {ACK, ACK} only, transmitting {NACK, ACK} only, transmitting {ACK, NACK} only, transmitting {NACK, NACK} only, transmitting {ACK, ACK} and SR simultaneously, transmitting {NACK, ACK} and SR simultaneously, transmitting {ACK, NACK} and SR simultaneously. It is about <NUM>% probability that the current SR will be dropped; however, this will not lead to unnecessary retransmission of transport block.

In a further embodiment, a base station configures four resources as SR resources. When a SR is transmitted and a HARQ-ACK message is not, one of the four resources is used to transmit SR, where two other resources of the four resources either correspond to different traffic types, respectively, e.g., eMBB and URLLC traffic, or correspond to different lengths of TTI, e.g., sTTI and TTI, or where three of the four resources correspond to different traffic types, respectively, e.g., eMBB, mMTC, and URLLC, or correspond to different lengths of TTI, e.g., sTTI_2OS, sTTI_7OS, and TTI. When the SR and the HARQ-ACK need to be transmitted simultaneously but simultaneous transmission is not supported, only the HARQ-ACK information is transmitted and the SR transmission is abandoned. When the SR and the HARQ-ACK needs to be transmitted simultaneously and simultaneous transmission is supported, transmission is performed within the configured HARQ-ACK and SR resources, where different meanings are represented. When HARQ-ACK is <NUM> bits, four resources are allocated for HARQ-ACK to represent {ACK, ACK}, {NACK, ACK}, {ACK, NACK}, and {NACK, NACK}. Here, with the four SR resource, there are eight resources in total, representing transmitting {ACK, ACK} only, transmitting {NACK, ACK} only, transmitting {ACK, NACK} only, transmitting {NACK, NACK} only, transmitting {ACK, ACK} and SR simultaneously, transmitting {NACK, ACK} and SR simultaneously, transmitting {ACK, NACK} and SR simultaneously, and transmitting {NACK, NACK} and SR simultaneously, where it is preferable to use the same resource to transmit SR only and to transmit {NACK, NACK} and SR simultaneously, as shown in Table <NUM> below.

In some embodiments, a HARQ-ACK message is <NUM> bits and the simultaneous transmission of ACK/NACK and SR is implemented in a bundling way, where the SR only mode may differentiate different traffic types and transmitting with ACK/NACK simultaneously may also differentiate different traffic types, as shown in Table <NUM> below. Here, when transmitting ACK/NACK and SR simultaneously, even if detection of a PDCCH is missed (e.g., where the UE believes to message is SR only but the base station believes it to be ACK/NACK + SR), the UE transmits SR_1 and SR_2 which the base station recognizes as NACK, thereby triggering retransmission and remedying the problem of missed PDCCH detection and improving reliability. As the probability of transmitting ACK is higher, preferably, SR_1 is chosen to be cyclic shift (CS)=<NUM>, SR_2 to be CS=<NUM>, SR_3 to be CS=<NUM>, and SR_4 to be CS=<NUM>.

As described above, in some embodiments, the invention provides uplink information transmission methods that may be used to transmit more effective information with more efficient resource savings when transmitting SR and HARQ-ACK simultaneously. In accordance with various embodiments, such methods avoid allocating excessive sequence resources that leads to decreased multiplexing capacity and thus improves the system resource utilization.

In some embodiments, a sequence-based sPUCCH signal includes up to <NUM> bits for HARQ-ACK transmission in <NUM>/<NUM>-symbol in a shortened TTI (sTTI). In order to address resource overhead concerns, when considering simultaneous transmission of SR and HARQ-ACK message, two alternatives are disclosed in accordance with two embodiments of the invention.

For transmission mode (TM) <NUM>\<NUM>\<NUM> or TM <NUM>\<NUM>\<NUM>\<NUM> scheduling by DCI Format 1A in <NUM>-symbol of a sTTI, two PUCCH resources shall be allocated for <NUM>-bit HARQ-ACK transmission. The multiplexing between <NUM>-bit ACK/NACK and SR with only one SR-PUCCH resource is given in Table <NUM> below.

In a sTTI with SR opportunity, a UE uses the allocated SR resource CS_SR to transmit SR if there is only SR transmission in this sTTI. If only <NUM>-bit HARQ-ACK transmission is expected, the UE can utilize the allocated HARQ-ACK resources CS_A and CS_N to transmit ACK and NACK respectively. In case of simultaneous transmission of SR and <NUM>-bit NACK, UE can use SR resource CS_SR for the transmission of NACK and SR. In this case, the discontinuous transmission (DTX) of PDCCH would be regarded as NACK at the eNB side. When SR and <NUM>-bit ACK are to be transmitted in the same sTTI, UE can simply transmit CS_A, while eNB would not be able to distinguish ACK only transmission and SR + ACK transmission. In other words, SR is dropped in this case. Alternatively, the UE can also transmit both CS_A and CS_SR to distinguish this case by causing a higher peak to average power ratio (PAPR).

For TM <NUM>\<NUM>\<NUM>\<NUM> scheduling not by DCI Format 1A, four PUCCH resources for <NUM>-bit ACK/NACK transmission needs to be configured in <NUM>-symbol sTTI without SR opportunities. However, HARQ-ACK bundling can be used in sTTI with SR opportunity. In this case, two PUCCH resources are configured to HARQ-ACK and the same multiplexing mechanism as Table <NUM> can be applied.

As shown in Table <NUM> below, two PUCCH resources are configured to SR in <NUM>-symbol sTTI. As an enhancement of Alternative <NUM> described above, the two resources CS_SR1, CS_SR2 can be used to further distinguish between <NUM>-bit ACK + SR transmission and <NUM>-bit NACK + SR transmission.

Based on the alternatives discussed above, the PUCCH resource overhead can be relieved. In accordance with some embodiments, a NR scheduling request protocol, method and system are disclosed. In LTE, scheduling request (SR) is used to request resources for uplink data transmission. A switching on/off mechanism carrying only one state of SR is used. Specifically, when only a positive SR is transmitted, a UE shall use PUCCH Format <NUM> to transmit on its assigned SR resource, otherwise a UE shall transmit nothing for a negative SR. In some embodiments, the SR-triggered uplink grant-based data transmission design considers applicable reliability and latency requirements, including URLLC, when assessing different design proposals. This implies that the on/off-switching mechanism used in LTE cannot provide enough information for the UL grant in NR.

In NR, multiple services with different reliability and latency requirements, e.g. eMBB and URLLC are supported. Different services may use different scheduling numerologies to meet the design metrics. In such case, the SR in NR should distinguish the scheduling for different services. Specifically, the short PUCCH format should be the baseline for HARQ-ACK feedback for URLLC to meet the low latency. That means, if a SR is transmitted in the long PUCCH format, the triggered traffic shall always be eMBB data. But, for the SR transmitted in short PUCCH, one bit SR with two SR configurations should be used to distinguish the scheduling from eMBB and URLLC.

In one embodiment, at least for the SR transmitted in short PUCCH, one bit SR with two SR configurations are used to distinguish the scheduling for eMBB and URLLC. Based on a predetermined sequence selection for up to 2bits UCI. two or four configured sequences are needed for <NUM>/<NUM>-bit UCI. Considering the simultaneous transmission of <NUM>/<NUM>-bit ACK/NACK and SR, a UE shall configure <NUM> sequence resources for SR. Combining with the two SR configurations used to distinguish different services, a total of <NUM> SR configurations are required. This will cause a large overhead of PUCCH resources. One way to solve this problem is to bundle the 2bits UCI to reduce the amount of needed PUCCH resources for simultaneous transmission of 2bits ACK/NACK and SR. Then <NUM> SR configurations are needed. Table <NUM> below shows an example for the multiplexing between SR and <NUM>-bit ACK/NACK within a short PUCCH with SR opportunity, in accordance with one embodiment. The four SR configurations are defined as CS_SR1,CS_SR2,CS_SR3 and CS_SR4 respectively. For the simultaneous transmission of Bundled ACK/NACK and SR, the SR configuration used for bundled NACK is the same as the configuration for SR only transmission. That is to avoid possible ambiguity when PDCCH is missed. In some embodiments, a one bit SR with four SR configurations is defined for SR transmission in short PUCCH based on sequence selection.

Claim 1:
A method performed by a first communication node, comprising:
configuring four resources as four scheduling request, SR, resources for transmitting a scheduling request from a second communication node to the first communication node, wherein:
a first resource of the four resources is selectively allocated when only the scheduling request without transmission of any hybrid automatic repeat request acknowledgement, HARQ-ACK, message is to be transmitted, and a second resource and a third resource are allocated for transmitting the scheduling request for a first traffic type and a second traffic type, respectively;
the first resource of the four resources is also selectively allocated when both the scheduling request and a HARQ-ACK message comprising two bits {NACK, NACK} are to be transmitted simultaneously,
each of the other three of the four resources is allocated to simultaneously transmit both the scheduling request and a respective one of two-bit HARQ-ACK messages {ACK, ACK}, {NACK, ACK}, {ACK, NACK}, and
receiving the scheduling request from the second communication node.