Comparison of several space diversity techniques for MLSE receivers in mobile communications

Several space diversity techniques for a maximum-likelihood sequence estimation receiver applied to digital mobile radio are considered and compared. Space diversity reception helps to overcome the frequency selective fading that is a common problem in mobile radio environment. Many papers have been devoted to the space diversity techniques but only few of them consider the diversity reception combined with the MLSE receiver. For such a receiver two groups of structures can be specified-combining/selection at the “sample level” and combining/selection at the “metric level”. For each group the authors investigate a few particular structures. They also define new criteria for the optimal combining. All the structures are compared by means of the computer simulation and the results are presented for typical channel models