Convolutional codes with correlated diversity and non-coherent orthogonal digital modulation

The performance analysis for binary convolutional codes and non-coherent, orthogonal digital modulation used on a Rayleigh fading channel with independent diversity branches is given in [1]. We extend this analysis to the case with correlated branch diversity. We find that branch correlation degrades a noncoherent coded modulation system but the correlation coefficients must be above 0.50 to get appreciable losses. Our analysis holds for any number of diversity branches, and computations are presented for dual diversity. Finally, even in the correlated case, we find that diversity improves channel conditions for error correction coding as both techniques can be jointly deployed to give considerable performance improvement for fading channels.