DIFFERENTIALLY DETECTED GMSK SIGNALS IN CCI CHANNELS FOR MOBILE CELLULAR TELECOMMUNICATION SYSTEMS

The performance of conventional and decision feed-back differential detection receivers for GMSK signals transmitted in the presence of co-channel interference (CCI) and additive white Gaussian noise (AWGN) is evaluated. For the interference, we adopt a model which includes N statistically independent static as well as faded CCI. Various bit-error-rate (BER) performance evaluation results have indicated that the receiver under investigation performs better as compared to other more conventional receiver structures. Especially significant BER improvements have been obtained for the static CCI channel. For example, it was found that with a carrier-to-interference (C/I) ratio of 14 dB, the performance of a 2-bit decision feedback differential receiver outperforms a conventional 2-bit differential detector by more than 14 dB (at a BER = 10(-3)). For the faded CCI, the improvement is less: mainly they result in error-floor reductions of about half an order of magnitude. By comparing the performance of static and faded CCI, it was also found that for a given C/I, the performance of the former would depend on the number of interferers, whereas this is not the case for the latter.