Performance of a digital symbol synchronizer in cochannel interference and noise

The performance of a binary-quantized data-transition tracking loop symbol synchronizer operating in cochannel interference (CCI) and noise is examined for both binary phase-shift keying and quaternary phase-shift keying modulations. The CCI can be included in a previously known Markov chain model without increasing the number of states in the chain, but the cost of computing the transition probabilities increases exponentially with the number of interferers. It is shown that a first-order Markov model and simulation are in close agreement for some important applications. The effect of interferer epoch on the degradation caused by the interference is investigated and the degradations in performance caused by CCI and by Gaussian noise are compared.