Advanced antenna systems for WCDMA: link and system level results

This contribution presents some link and system level simulation results obtained by a WCDMA base station equipped with an adaptive antenna system. The results show that the performance gain obtained by an advanced antenna system could be substantial compared to an ordinary sector covering system. The link simulations show that for a given SIR target in a single cell system, the capacity is increased considerably compared to a conventional single sector covering antenna system. It is also shown that the difference between the different adaptive antenna algorithms is marginal. The system level simulations have shown that the capacity performance is basically proportional to the number of orthogonal beams used in the base station. In cases where the conventional three sector reference system is not truly interference limited, the performance gain can be even higher. The system simulations have also shown that using more beam positions than those defining the set of orthogonal fixed beams slightly improves the performance. However the number of beam positions can be kept relatively small, in the order of twice the number of orthogonal beams, without significant loss