Algorithms for flexible equalisation in wireless communications

In this paper the requirements for a flexible equaliser architecture for wireless communications are discussed and illustrated with results from simulation. Decision Feedback Equalisers are compared in terms of their performance and computational requirements. It has been found that the recursive modified Gram Schmidt algorithm provides superior BER performance to the least squares lattice decision feedback lattice and the conventional RLS algorithm. In addition the problem of synchronising the equaliser to achieve best performance and exploit the multipath propagation of the wideband channel is addressed. For a two path Rayleigh fading channel model it is shown that best performance is obtained by synchronising the frame to the arrival time of the first multipath rather than the dominant path.