On Transmit-Diversity Based Multicast in Mobile Wireless Networks

Abstract

We investigate the variations of using the different transmit-diversity techniques for multicast in mobile wireless networks. In particular, we propose and study two different schemes using transmit-diversity for mobile multicast. First, we propose the antenna-beamforming-based mobile multicast scheme which derives the transmit antenna weights by formulating/solving an optimization problem to minimize the average Symbol Error Rate (SER) over all multicast receivers. The simulations results show that our proposed beamforming-based scheme achieves lower SER compared with the existing beamforming-based mobile multicast algorithms which either maximize the instantaneous combined Signal to Noise Ratio (SNR) averaged over all receivers, or maximize the worst-case instantaneous combined SNR among all multicast receivers. Second, we apply the antenna-selection scheme in mobile multicasting to achieve the low average SER. We identify that the antenna-selection scheme is suitable for the scenario where different receivers/receiver-groups in a multicast session, experiencing different channel qualities, need to receive different error-control data. The analyses and numerical results show that the proposed scheme improves the SER performance through selecting antennas with better channel qualities and can flexibly support various antenna configurations.