Optimization of transmit-antenna selection / equal gain transmission in Rayleigh fading channels

In this paper we investigate a scheme combining transmit-antenna selection (TAS) and equal gain transmission (EGT). The expected received SNR of the proposed systems is derived according to the probability distribution of channel fading. The algorithm of determining the minimum of required RF chains is put forward in terms of a given transmit antennas. A new phase quantization algorithm of optimum precoding vector was given, which has low complexity and can adapt the transmission rate of feedback channel. Simulation results demonstrate the superiority of the proposed systems. Comparing with 8 diversity EGT systems, the proposed systems only require 5 RF chains instead of 8 ones. In this case, the proposed algorithm with 4 bits phase quantization can mostly approach optimal performance. Therefore, the algorithm with more than 5 bits is meaningless for performance improvent.