Method, apparatus and computer program to map a cyclic shift to a channel index

摘要

From the network perspective, an uplink resource allocation (PDCCH) is sent that grants an uplink resource to a plurality of user equipments UEs, and the allocation has an indication of a cyclic shift CS for each of the plurality of UEs. The granted uplink resource is mapped to a downlink resource (PHICH) in dependence on the indicated CS for each of the plurality of UEs. The mapping is such that for a predetermined number of UEs being allocated a same uplink resource in a single MU-MIMO uplink resource allocation grant, each pair of said predetermined number of UEs which map to an adjacent downlink resource exhibit an optimized CS relative to one another. The network sends to each of the respective plurality of UEs on the respective mapped downlink resource an indication (ACK/NACK) about data received (on a PUSCH). Apparatus, method, and computer programs for network and UE side implementations are detailed.

主权项

1. A method comprising:
receiving an uplink resource allocation in a wireless communications network and an indication in the granted uplink resource allocation of a cyclic shift; sending data on the granted uplink resource; mapping the granted uplink resource to a downlink resource in dependence on the indicated cyclic shift, such that user equipment-specific cyclic shifts mapped to adjacent downlink resources are non-adjacent cyclic shifts relative to one another; and receiving on the mapped downlink resource an indication about the sent data; and wherein the cyclic shift is for a demodulation reference signal and the indication of the cyclic shift is a dynamic cyclic shift indicator of three bits that indicates a user-specific cyclic shift.