Study of recursive equalisers for data transmission with a comparison of the performance of six systems

Adaptive and automatic quantised feedback equalisers of telephone lines for data transmission are studied. In particular, equalisers which use a steepest-descent algorithm with a minimum mean square error criterion are considered, and the effect of 2-level quantisation on the mean square error in the steady state and on the conditions of stability are analysed. The effect of the `random walk¿ of the tap coefficients on the mean square error in the steady state is also investigated. Finally, a comparison of the performance of six equalisation schemes is made using computer simulation. These schemes include nonrecursive and hybrid networks, with and without signal quantisation.