Power Allocation for Tri-node Cooperative Communication of Gaussian Channel Gains

Channel capacity is usually undetermined in cooperative communication because of the various power allocations. In order to improve the channel capacity, power allocation for tri-terminal cooperative communication is discussed for Gaussian channel gains in EGC model and MRC model. The optimum power allocation algorithm, viewing channel capacity as the destination function, is presented. The paper obtains the results that when the gain variance of the source-node-to-destination-node channel is larger than that of the source-node-to-relay-node channel, source node can transmit information to the destination node directly. When the product of the power from the source node and the variance of the channel gain from source node to destination node is much smaller than the other products, source node can transmit information via the relay nodes completely. In other cases, source node can partly transmit to the destination node via relay nodes and partly transmit information to the destination node directly. And experimental results show that the scheme is effective.