Downlink control channel design and signaling for beamformed systems
Transmit and/or receive beamforming may be applied to the control channel transmission/reception, e.g., in mmW access link system design. Techniques to identify candidate control channel beams and/or their location in the subframe structure may provide for efficient WTRU operation. A framework for beam formed control channel design may support varying capabilities of mBs and/or WTRUs, and/or may support time and/or spatial domain multiplexing of control channel beams. For a multi-beam system, modifications to reference signal design may discover, identify, measure, and/or decode a control channel beam. Techniques may mitigate inter-beam interference. WTRU monitoring may consider beam search space, perhaps in addition to time and/or frequency search space. Enhancements to downlink control channel may support scheduling narrow data beams. Scheduling techniques may achieve high resource utilization, e.g., perhaps when large bandwidths are available and/or WTRUs may be spatially distributed.
1 . A wireless transmit/receive unit (WTRU) comprising a processor configured to:
receive downlink control information (DCI), the DCI comprising scheduling information for a plurality of physical uplink shared channel (PUSCH) repetitions, wherein the DCI comprises a first indication of a first sounding reference signal (SRS) ID associated with at least a first PUSCH repetition of the plurality of PUSCH repetitions and a second indication of a second SRS ID associated with at least a second PUSCH repetition of the plurality of PUSCH repetitions, wherein the first SRS ID is associated with a first transmission beam, and the second SRS ID is associated with a second transmission beam;
transmit the first PUSCH repetition in accordance with the first SRS ID indicated in the DCI; and
transmit the second PUSCH repetition in accordance with the second SRS ID indicated in the DCI.
2 . The WTRU of claim 1 , wherein the DCI further comprises starting symbol and symbol duration information associated with the plurality of PUSCH repetitions.
3 . The WTRU of claim 1 , wherein the DCI further comprises resource block information associated with the plurality of PUSCH repetitions.
4 . The WTRU of claim 1 , wherein the first PUSCH repetition and the second PUSCH repetition each comprises repetitions of a same transport block.
5 . The WTRU of claim 1 , wherein the first and second PUSCH repetition are transmitted in accordance with uplink (UL) data control channel beam indicated in a physical downlink control channel (PDCCH).
6 . The WTRU of claim 1 , wherein the processor is configured to transmit the first or second PUSCH repetition based on an offset between a physical downlink control channel (PDCCH) and a PUSCH.
7 . The WTRU of claim 6 , wherein the DCI comprises spatial information, and wherein the processor is configured to determine the offset based on the spatial information.
8 . The WTRU of claim 6 , wherein an indication of the offset is received via a radio resource control (RRC) signal or a medium access control (MAC) control entity signal.
9 . The WTRU of claim 1 , wherein a physical downlink shared channel (PDSCH) comprises spatial information, wherein the spatial information comprises the scheduling information, and wherein the processor is further configured to determine a validity of the scheduling information based on an acknowledgement corresponding to a downlink (DL) PDSCH.
10 . A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
receiving downlink control information (DCI), the DCI comprising scheduling information for a plurality of physical uplink shared channel (PUSCH) repetitions, wherein the DCI comprises a first indication of a first sounding reference signal (SRS) ID associated with at least a first PUSCH repetition of the plurality of PUSCH repetitions and a second indication of a second SRS ID associated with at least a second PUSCH repetition of the plurality of PUSCH repetitions, wherein the first SRS ID is associated with a first transmission beam, and the second SRS ID is association with a second transmission beam;
transmitting the first PUSCH repetition in accordance with the first SRS ID indicated in the DCI; and
transmitting the second PUSCH repetition in accordance with the second SRS ID indicated in the DCI.
11 . The method of claim 10 , wherein the DCI further comprises starting symbol and symbol duration information associated with the plurality of PUSCH repetitions.
12 . The method of claim 10 , wherein the DCI further comprises resource block information associated with the plurality of PUSCH repetitions.
13 . The method of claim 10 , wherein the first PUSCH repetition and the second PUSCH repetition each comprises repetitions of a same transport block.
14 . The method of claim 10 , wherein the first and second PUSCH repetition are transmitted in accordance with uplink (UL) data control channel beam indicated in a physical downlink control channel (PDCCH).
15 . The method of claim 10 , further comprising transmitting the first or second PUSCH repetition based on an offset between a physical downlink control channel (PDCCH) and a PUSCH.
16 . The method of claim 15 , wherein the DCI comprises spatial information, and wherein the further comprising determining the offset based on the spatial information.
17 . The method of claim 15 , wherein an indication of the offset is received via a radio resource control (RRC) signal or a medium access control (MAC) control entity signal.
18 . The method of claim 10 , wherein a physical downlink shared channel (PDSCH) comprises spatial information, wherein the spatial information comprises the scheduling information, and wherein the method further comprising determining a validity of the scheduling information based on an acknowledgement corresponding to a downlink (DL) PDSCH.