Cooperative relaying protocol for energy-constrained ad hoc networks

Cooperative diversity is a powerful tool that can be used to improve the performance of wireless networks. The use of directional antennas has also shown to offer an effective way for efficient bandwidth utilisation. In this study, the authors investigate the effect of both the transmission power and the number of cooperative relays on the maximum achievable throughput in energy-constrained cooperative ad hoc networks with directional antennas. In particular, the authors develop an analytical model for the network throughput in terms of the number of cooperative relays and nodes´ transmission power. Using our model, we determine the optimum number of relays for a given transmission power, and the optimum transmission power for a given number of relays. Furthermore, we propose a cooperative relaying protocol that utilises the above optimal values to maximise the achievable throughout in such energy-constrained networks. The obtained analytical results as well as the performance of the proposed protocol are validated by simulations over a Rayleigh fading channel.