Green BICM-OFDM based cooperative communications using bargaining game algorithm

In this paper, a relay-based energy-efficient cooperative communication strategy is proposed, under the hypothesis that the relay transmits with power drawn from energy-harvesting (EH) sources. Assuming a deterministic EH model under which the harvested amount of energy is known prior to transmission, a spectrally efficient adaptive Bit-Interleaved Coded (BIC) OFDM modulation scheme has been investigated. To guarantee the successful reception of a packet, Automatic Repeat Request (ARQ) protocol has been adopted. Assuming a long term static channel, the expected goodput (EGP) metric is used as cost function to be optimized. The most significant step-ahead of the proposed approach with respect to state-of-the-art is to increase the cooperation gain by using a bargaining game algorithm. Since most renewable sources are highly intermittent, they can induce significant fluctuation on the available power. The bargaining game algorithm takes into account the energy status of the relay and helps the source node to decide whether to cooperate or not with the relay. Achieved simulation results show that the bargaining game algorithm actually helps the nodes to select the right strategy, with a substantial goodput improvement, in particular when the energy availability of relay becomes intermittent due to the harvesting.