Effects of Dominant Other-Sector Interference on Multi-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 HSDPA system are provided. The dual antenna RAKE receiver serves as baseline reference. Link-level simulation results are confirmed by a novel analytical expression that in flat Rayleigh fading and for uncorrelated rx antenna branches provides spatial interference suppression mean SINR gain as a function of the dominant other-sector interference ratio (DIR). It is shown that the MMSE receiver’s spatial interference suppression gain depends heavily on the amount of experienced DIR. The higher the DIR the higher is the SINR gain. Nevertheless, seen on network level 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, dynamic range limitations hinder translation of the full SINR gain into sector throughput.