N-branch diversity reception of M-ary DPSK signals in slow and nonselective Nakagami fading

The problem of diversity reception of M-ary differential phase shift keying modulated signals in the presence of additive white Gaussian noise and Nakagami-distributed slow and nonselective fading is addressed. N-branch selection diversity and maximal ratio combiners are considered. The average symbol error rate is analytically evaluated in terms of integral expressions, which can be easily computed via numerical integration routines. Numerical results are presented that allow one to point out those operational situations where diversity systems can operate successfully to mitigate the degrading effects of short-term fading.