SUB-BAND DISCRETE FOURIER TRANSFORM-SPREAD-ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING FOR DOWNLINK
Various aspects of the present disclosure relate to sub-band discrete Fourier transform-spread-orthogonal frequency division multiplexing for downlink. An apparatus, such as a user equipment (UE), receives signaling comprising a configuration for common Discrete Fourier Transform (DFT) spreading length of a DFT-s-OFDM waveform, the common DFT spreading length configured for a common sub-band generated using contiguous frequency domain resource blocks for a group of UEs. The UE receives a DFT-s-OFDM waveform over at least one of common channel, control channel, or data channel within the common sub-band and according to the common DFT spreading length of the DFT-s-OFDM waveform.
1 . A network equipment for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the network equipment to:
transmit signaling comprising a configuration for a common Discrete Fourier Transform (DFT) spreading length of a DFT-s-OFDM waveform, the common DFT spreading length configured for a common sub-band generated using contiguous frequency domain resource blocks for a group of user equipment (UEs); and
transmit a DFT-s-OFDM waveform over at least one of common channel, control channel, or data channel within the common sub-band and according to the common DFT spreading length of the DFT-s-OFDM waveform.
2 . The network equipment of claim 1 , wherein the at least one processor is configured to cause the network equipment to determine the common DFT spreading length of the DFT-s-OFDM waveform based on one or more of a peak to average power ratio (PAPR) gain for the common sub-band used in a connected mode for the group of UEs, or a synchronization signal block (SSB) or control resource set (CORESET) #0 bandwidth for an initial sub-band used for initial access.
3 . The network equipment of claim 2 , wherein the at least one processor is configured to cause the network equipment to determine a number of sub-bands within a bandwidth part (BWP) or a carrier and based at least in part on the BWP or a carrier total bandwidth and the PAPR gain.
4 . The network equipment of claim 1 , wherein the at least one processor is configured to cause the network equipment to determine a grouping respective configuration applicable for the group of UEs to be served within the common sub-band and the common DFT spreading length of the DFT-s-OFDM waveform based at least in part on serving beams or synchronization signal block (SSB) beams of the group of UEs.
5 . The network equipment of claim 1 , wherein the at least one processor is configured to cause the network equipment to determine the configuration and the group of UEs to be served with the common sub-band and the common DFT spreading length of the DFT-s-OFDM waveform based at least in part on beam coverage of the network equipment or a proximity of each UE to the network equipment.
6 . The network equipment of claim 1 , wherein the configuration is semi-static and identifies the common sub-band containing common spreading length and location of frequency resources of the common sub-band.
7 . The network equipment of claim 1 , wherein the configuration comprises time domain information for time resources for each UE of the group of UEs mapped prior to applying DFT, and wherein the time domain information is indicated by a bit map of time resources or via interleaving information indicating a location of the time domain resources.
8 . The network equipment of claim 1 , wherein the at least one processor is configured to cause the network equipment to signal the configuration including time-frequency resource for transmission to each UE of the group of UEs within the common sub-band via one or more of dedicated DCI, via group downlink control information (DCI), or via radio resource control (RRC), or a combination thereof.
9 . The network equipment of claim 1 , wherein the configuration comprises information of one or more of a group common demodulation reference signal (DMRS) type, a DMRS waveform, or DMRS location within the common sub-band.
10 . The network equipment of claim 1 , wherein the at least one processor is configured to cause the network equipment to signal the configuration via one or more of a row index of a table sent via dedicated downlink control information (DCI) to each UE of the group of UEs, via group DCI, or via radio resource control (RRC).
11 . The network equipment of claim 1 , wherein the configuration comprises information of the length and location of frequency resources of the common sub-band.
12 . A user equipment (UE) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive signaling comprising a configuration for common Discrete Fourier Transform (DFT) spreading length of a DFT-s-OFDM waveform, the common DFT spreading length configured for a common sub-band generated using contiguous frequency domain resource blocks for a group of UEs; and
receive a DFT-s-OFDM waveform over at least one of common channel, control channel, or data channel within the common sub-band and according to the common DFT spreading length of the DFT-s-OFDM waveform.
13 . The UE of claim 12 , wherein the configuration comprises information of the spreading length and location of frequency resources of the common sub-band.
14 . The UE of claim 12 , wherein the configuration comprises time domain information for time resources for each UE of the group of UEs mapped prior to applying DFT, and wherein the time domain information is indicated by a bit map of time resources or via interleaving information indicating a location of the time domain resources.
15 . The UE of claim 12 , wherein the at least one processor is configured to cause the UE to receive the configuration including time-frequency resource for transmission to each UE of the group of UEs within the common sub-band via one or more of dedicated DCI, via group downlink control information (DCI), or via radio resource control (RRC), or a combination thereof.
16 . The UE of claim 12 , wherein the configuration comprises information of one or more of a group common demodulation reference signal (DMRS) type, a DMRS waveform, or DMRS location within the common sub-band.
17 . The UE of claim 12 , wherein the at least one processor is configured to cause the UE to receive the configuration via one or more of a row index of a table sent via dedicated downlink control information (DCI), via group DCI, or via radio resource control (RRC).
18 . The UE of claim 12 , wherein the configuration comprises information of the length and location of frequency resources of the common sub-band.
19 . A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
receive signaling comprising a configuration for common Discrete Fourier Transform (DFT) spreading length of a DFT-s-OFDM waveform, the common DFT spreading length configured for a common sub-band generated using contiguous frequency domain resource blocks for a group of user equipment (UE); and
receive a DFT-s-OFDM waveform over at least one of common channel, control channel, or data channel within the common sub-band and according to the common DFT spreading length of the DFT-s-OFDM waveform.
20 . A method performed by a user equipment (UE), the method comprising:
receiving signaling comprising a configuration for common Discrete Fourier Transform (DFT) spreading length of a DFT-s-OFDM waveform, the common DFT spreading length configured for a common sub-band generated using contiguous frequency domain resource blocks for a group of UEs; and
receive a DFT-s-OFDM waveform over at least one of common channel, control channel, or data channel within the common sub-band and according to the common DFT spreading length of the DFT-s-OFDM waveform.