On the optimality of M-group decentralized STBC for cooperative networks

This paper investigates an optimal decentralized Space-Time Block Coding (STBC) transmission strategy given an overhead constraint. The design of protocols for a cooperative network is formulated as an optimization problem. By solving the proposed problem, M-group decentralized STBC is proved to be the optimal strategy when neither central control nor inter-relay communications is permitted. The optimality of M-group holds in not only ideal Rayleigh fading but also in more realistic scenarios. Simulation results verify the analysis.