Component-Interleaved Receive MRC with Rotated Constellation for Signal Space Diversity

A signal space diversity (SSD) scheme combined with receive maximal ratio combining (MRC) was investigated in order to achieve more diversity gain in fading channels. By approximating noise as a Gaussian distribution after performing receive MRC, an exact expression for the symbol error rate for SSD schemes combined with receive MRC in Rayleigh fading channels can be derived for 4-QAM and 16-QAM. By performing simulations, the accuracy of our analysis, which exactly coincides with the empirical simulations for Rayleigh fading channels, was verified. Furthermore, using the formula derived by using the upper bound approach, it can be confirmed that the diversity order is 2 M_R where 2 stems from SSD and M_R from receive MRC with multiple receive antennas. Numerical evaluation performed using the formula under various conditions indicated that the angle rotation affects the performance; this numerical evaluation had low computational complexity.