Performance of north American digital cellular system with frequency-offset diversity and differential detection

The bit error rate performance of North American digital cellular system using frequency-offset diversity combining with differential detection and soft decision Viterbi decoding is evaluated. The transmitter is simulated as per dual-mode digital cellular standard IS-54. The channel is simulated as a frequency-selective fast Rayleigh fading channel corrupted by additive white Gaussian noise and cochannel interference. Frequency-offset diversity and soft-decision Viterbi decoding to cope with the severe frequency-selective distortions caused by the propagation phenomena are properly modeled for the computer simulation. The bit error rate results are plotted for different channel parameters. The computed results show that the combination of diversity and convolutional coding results in a very significant improvement compared to the differential detector receiver