Analysis of Transmit Antenna Selection With Switch-and-Examine Combining With Postselection at the Receiver Over Rayleigh Fading Channels

A diversity-combining system using transmit antenna selection at the transmitter and switch-and-examine combining with postselection (TAS/SECPS) at the receiver is proposed. This system has lower processing complexity as compared with the existing TAS schemes with maximal-ratio combining and selection combining (TAS/SC) at the receiver. The performance of the TAS/SECPS system with different modulation schemes over independent and nonidentically distributed Rayleigh fading channels is examined. The expressions of average output signal-to-noise ratio (SNR) and symbol error rate (SER) are derived and validated by simulation. It is shown that the proposed TAS/SECPS is able to achieve similar average output SNR and SER performance as compared with TAS/SC when the predetermined SNR threshold is optimized. Moreover, the TAS/SECPS requires less number of channel estimates.