Performance analysis of transmit antenna selection-maximal ratio combining relay systems over non-identical channel estimation error

This study investigates the performance analysis of a transmit antenna selection–maximal ratio combining relay system over non-identical channel estimation error. The proposed system selects both relay and user terminal with a maximum signal-to-noise ratio (SNR) using feedback information. The exact closed-form expression of the proposed system for the outage probability and symbol error rate (SER) is derived in the presence of non-identical channel estimation error. Using the approximated probability density function, the authors quantify the diversity order for the SER and outage probability. From the above results, the diversity order of the proposed system is proportional to the number of relay nodes and user terminals. Thus, the diversity order of the proposed system is superior to that of the previous selection systems. The diversity order of the proposed system is independent of the number of receive antennas at the relay and user terminal and the channel correlation coefficient. Furthermore, the SNR gain of the proposed system is in proportion to the sum of the channel correlation coefficients and the number of receive antennas at the relay and user terminal.