On the application of uplink optimum combining to base station reception

This paper presents some results on the gains obtained by applying optimum combining in a multiple antenna base station receiver for a TDMA system. Performance is assessed at both the link level and the network level, e.g. accounting for factors such as loading, frequency hopping, lack of synchronism between signals and number of antennas. It is shown that the radio link gain of optimum combining is rather limited in most situations, compared to the gain achievable in ideal conditions, and also that this gain cannot easily be translated into a capacity increase. Fractionally loaded networks with slow frequency hopping seem to present most promise in this respect