Outage Capacity of Two-Phase Space-Time Coded Cooperative Multicasting

Multi-path fading poses severe limitations to the reliable transmission rate of multicast in wireless networks. To improve robustness and throughput, cooperation among the nodes of the network can be used to crate spatial diversity and thus overcome fading impairments. This paper proposes a two-phase, space-time coded, cooperative multicast protocol, and analyzes its capacity performance in finite size networks. We consider two different channel state information (CSI) scenarios: (1) no transmit CSI at the base station and receive CSI at the multicast nodes; (2) channel knowledge at the base station of base-station-to-users channels but not of intra-user channels, and receive CSI at the multicast nodes. Results show that cooperation is worthwhile for sufficiently large networks and for the low SNR regime.