Performance analysis of scheduled TAS with MRC in the presence of non-identically delayed feedback channels

This paper studies the performance of a scheduled transmit antenna selection (TAS) with maximal ratio combining (MRC) in the presence of non-identically delayed feedback channels. This paper derives the probability density function of the scheduled TAS with MRC under non-identical feedback delay channels. Using the distribution, this paper derives exact closed-form expressions of the scheduled TAS with MRC for the outage probability and symbol error rate (SER) with M-ary phase shift keying and quadrature amplitude modulation as well as the ergodic capacity under the non-identical feedback delay channels. We also quantify the diversity order of the outage probability and SER. The asymptotic results show that the receive antenna diversity is only available under non-identical feedback delay channels, while the multi-user diversity and transmit spatial diversity are diminished compared to the perfect channel environment. Further, the performance of the scheduled TAS with MRC in the presence of non-identical feedback delay is significantly improved by the number of receive antennas, while the impact of the number of transmit antennas or correlation coefficients of feedback delay is insignificant.