Adaptive channel identification algorithms for GSM digital mobile radio

The paper is concerned with adaptive channel identification algorithms for use within the highly time variant radio communications environment. More specifically the problem of Viterbi equaliser coefficient computation within the GSM digital mobile radio system is considered. Within the paper algorithms which employ a priori knowledge of the time variant characteristics of the channel in order to reduce steady state estimation error due to channel time variation are presented. Theoretical analysis of the stability, convergence rate and steady state performance of the algorithms is presented and it is shown that under general time variant channel conditions the algorithms can result in improved performance over conventional algorithms. Under GSM specific channel conditions, however, it is shown that additive noise levels are in general too high and data block lengths too short to enable significant performance advantage to be achieved