Proficient User and Antenna Selection Strategies for Multi-carrier MIMO Communications Using Adjacent Sub-carrier Clustering.

In this paper, authors propose novel limited feedback scheduling algorithms for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) broadcast channels (BC). Users feed back the maximum signal-to-interference-plus-noise ratio (SINR) and the index of the corresponding transmit antenna to base station. Here, it is proposed that a given user transmits back the maximum SINRs corresponding to each transmit antenna. It is shown that by this process the overall throughput improves significantly with comparatively small increase in feedback overhead (FO). Further, FO increases linearly with number of sub-carriers used in MIMO–OFDM. Adjacent sub-carriers experience similar channel conditions. Hence, they are grouped into clusters to reduce FO. Moreover, we propose that feedback of each user should consist of sum of the logarithmic values of the maximum SINRs corresponding to each transmit antenna for all sub-carriers present in a given cluster. The logarithmic based algorithm below a specific cluster size attains system sum-rate comparable to scheduling algorithms without sub-carrier grouping but with a reduction in FO by a factor equal to cluster size. [ABSTRACT FROM AUTHOR]