Effects of dominant other-sector interference on dual Rx-antenna HSDPA performance

Link level SINR simulation results and network level sector throughput simulation results that quantify the benefit of dual antenna MMSE reception in a macrocellular WCDMA/HSDPA system are provided. Dual antenna RAKE receiver performance serves as baseline reference. Link-level simulation results are accompanied by a novel analytical expression that in flat Rayleigh fading and for uncorrelated rx-antenna branches describes spatial interference suppression mean SINR gain as function of a dominant other-sector interference ratio (DIR). It is shown that the MMSE receiver's spatial interference suppression gain heavily depends on the amount of experienced DIR. The higher the DIR the higher the SINR gain. Nevertheless, seen on network level the SINR gain turns into moderate sector throughput gain, well below 50%. This is due to the fact that high DIR situations are rare in the investigated macrocellular scenario. Moreover, the logarithmic relation between SINR and capacity hinders translation of the full SINR gain into HSDPA sector throughput.