The General Gaussian Relay Channel: Analysis and Insights

We study the problem of power consumption in the general Gaussian relay channel which is composed of one source– destination pair willing to communicate at a fixed transmission rate with the possibility of using an available relay node. The aim is to find the route that requires the least total transmit power to achieve reliable communications at the given rate. The system model is analyzed and some valuable insights to the performance of larger multihop– based networks are drawn. We show that power consumption depends on the route selection which in turn depends on the location of the nodes, the transmission rate, and the accessing scheme. Two classes of accessing schemes, cooperative and non–cooperative accessing, that offer a tradeoff between performance and complexity are presented and compared. Results show that gains exceeding 7 dB in transmit power are achieved in some cases when using the relay node. Moreover, we propose various enhancement techniques to improve the performance of the non– cooperative accessing schemes and we present results for a network model with two relay nodes.

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