Adaptive Antenna Techniques Applied to Multicast Services in Wireless Networks

This paper evaluates and compares different adaptive antenna techniques applied in the context of multicast services. Traditional unicast algorithms, such as the matched filter, zero-forcing, TomlinsonHarashima precoding, and switched fixed beams are formulated for the multicast case. Algorithms which try to improve the performance of the worst user within the multicast group are also analyzed and a new algorithm called USMF is proposed. It is seen that the techniques which treat all the users alike do not perform well when compared to those which focus on the worst user. The spatial correlation of the channel is shown to have a significant impact on the results. The presence of line-of-sight is verified to be beneficial to the performance of the proposed algorithm and the switched fixed beams. Other aspects, such as the transmitter/receiver design and the impact of the multicast group size, are investigated as well. Index Terms – Multicast services, transmit processing, adaptive antennas.