Average error rate of NCFSK with multi-branch post-detection switched diversity
We investigate the performance of non-coherent frequency shift keying (NCFSK) with multi-branch post-detection switched diversity systems. After an appropriate statistical description of the square-law detector output, we derive generic formulas for the symbol/bit error probability of NCFSK for both switch and stay combining (SSC) and switch and examine combining (SEC) schemes. We show that while the SSC scheme does not benefit from more than two diversity paths when the paths are identically distributed, the error performance of SEC improves as the number of antenna paths increases. We consider two detection schemes for NCFSK, one for M-ary FSK and another limited to only BFSK. We show that the second scheme leads to lower error probability performance when both are used to detect binary signals. The mathematical formalism is illustrated with a number of selected numerical examples. Copyright (C) 2004 John Wiley Sons, Ltd.
switched diversity frequency shift keying diversity techniques post-detection combining error rate analysis