Combining space-time block coding with diversity antenna selection for improved downlink performance

Abstract

A closed-loop method combining N-out-of-M antenna selection and space-time block coding from the selected antennas is proposed and studied in this paper. Performance is evaluated for WCDMA parameters in both frequency nonselective Rayleigh fading channels and in frequency selective (Vehicular A) channels. Operation in intra- and inter-cell dominant interference scenarios is considered. Numerical results show that the additional antenna selection procedure brings a supplementary uncoded BER performance improvement in the range of approximately 2-3.5 dB for flat-fading channels and 0.8-1.5 dB for frequency selective channels (@BER=12%). A suboptimum selection scheme requiring only a single bit for antenna selection is also presented. In addition, the impact on performance of errors in the feedback channel is investigated in this paper.