When SNR = 0 dB and the number of antennas was 60 or less, the spectral efficiencies of the CRCES and NRCES schemes were approximately 1.7 bit/(s*Hz) higher than those of CBRCS and NBS, respectively.
In an ideal environment with no noise, both CBRCS and CRCES are likely to have the same antenna subset.
The CBRCS score is 7.5x[10.sup.5], the NBS score is 1.2x[10.sup.3], and, finally, the CRCES and NRCES scores are 1.7 x [10.sup.7] and 1.7 x [10.sup.5], respectively.
CRCES is designed to maximize performance, whereas NRCES is designed to improve performance in terms of complexity.
The simulation results show that the proposed CRCES scheme has the highest spectral efficiency and performance level, especially at low SNR.