Spectrum efficiency optimization in a cellular packet data communication system
Peter Han Joo Chong, Cyril Leung · 2002
A simulation model of multiple co-channel interferers in a cellular communication system, for downlink traffic using non-coherent frequency shift keying modulation, is developed and used to investigate the bit error rate (BER) and block error rate (BKER) of the packet data traffic as a function of the number, n/sub I/, of interferers. It is found that for large n/sub I/ the interference signal can be modeled as white Gaussian noise of the same power spectral density (PSD) value. The results are used to determine the spectrum efficiency, E/sub s/, for different system configurations. The optimal value, K/sub opt/ of the cluster size is studied. With no fading or very slow Rayleigh fading, K/sub opt/ is small, typically less than 4. However, K/sub opt/ increases with the Doppler frequency. The use of FEC tends to lower K/sub opt/ but does not necessarily improve E/sub s/.