An efficiency multiuser diversity scheme with partial feedback on common uplink channel

In the multiple antenna multiuser systems, multiuser diversity technique is a simple but practical technique to increase system throughput, especially when many users exist. This, however, may cost too much radio resource for the feedback request of channel quality metrics for each user in every slot. By investigating the throughput performance of multiuser diversity system with random beamforming in the downlink broadcast channel, this paper proposes an efficient scheme with partial feedback of channel metric on the common uplink channel. The uplink feedback channel is sliced into many parallel orthogonal sub-channels and for every feedback sub-channel, a contention-based multiple access approach is used among all the users. Performance analysis proves that with the proper threshold setting for distinguishing a "good" channel, the system under the proposed scheme can pay much less for uplink feedback channel with little loss of system throughput, which is also means that the system could accommodate more users within given radio bandwidth of uplink channel.