Power Allocation for Multi-Relay Nodes Based on Signal-Noise-Ratio

Abstract

In wireless communication system, the cooperative diversity is a new space diversity mode. Power allocation plan aiming at maximizing the signal-noise-ratio (SNR) for multi-relay cooperative nodes system is discussed. Diversity signals are combined by the maximum ratio at the destination node. The research results show that 1) when the received noise level at destination node is very low, it can be neglected; 2) when the power allocation coefficients are proportional to the square of the channel gains from the source node to the relay nodes, the SNR of system is maximized in the maximum ratio combination model; and 3) When the received noise at destination node cannot be neglected, the power allocation coefficients are correlative to the received noise at destination node, the amplifying coefficients and the fading coefficients. The SNR of system can be enhanced by using the plan compared with traditional equal power allocation plan.