Performance of a digital symbol synchronizer in cochannel interference andnoise

The performance of a binary-quantized data-transition tracking loop symbol synchronizer operating in cochannel interference (CCI) and noise is examine d for both binary phase-shift keying and quaternary phase-shift keying modu lations. The CCI can be included in a previously known Markov chain model w ithout increasing the number of states in the chain, but the cost of comput ing the transition probabilities increases exponentially with the number of interferers. It is shown that a first-order Markov model and simulation ar e in close agreement for some important applications, The effect of interfe rer epoch on the degradation caused by the interference is investigated and the degradations in performance caused by CCI and by Gaussian noise are co mpared.