The effect of shadowing on GMSK land mobile radio system

摘要

Gaussian-filtered minimum-shift keying (GMSK) is proposed as effective digital modulation for mobile radio systems. The performance for GMSK is analyzed. Cochannel interference probabilities are evaluated for mobile radio systems operating in an environment where the fading is mitigated by adopting diversity reception. The protection ratio of the modulation and the cochannel interference probabilities are used to calculate the reuse distance and the number of channel sets needed for a cellular system. The conclusion is that the number of channel sets needed increases rapidly with the increase of standard deviation as the interference probability is fixed. With a high standard deviation users will suffer high interference and it is suggested that a greater reuse distance be used. For a given interference probability, a high protection ratio required by the modulation scheme will also increase reuse distance.