Diversity combining with MLSE equalisation

Abstract

Optimum diversity combining and equalisation applied to linear systems is realised using maximum likelihood sequence estimation. It is shown that each received signal should be applied to a filter which is matched to the corresponding diversity channel's impulse response. The output of this set of filters is simply summed, sampled at the symbol rate and input into a maximum likelihood sequence estimator. The performance of this structure is predicted by simulation with MSK and GMSK modulations using a GSM channel model. Even though GMSK is not linear, the nonlinearity is ignored and the receiver structure is made the same in both cases.