Relaying Node Selection Algorithm Based on Channel Capacity for Cooperative System

Cooperative communication is a promising technique that uses many relaying nodes to combat channel fading. To achieve better communication and lower computational cost, some relays in good condition should be selected from all available relays. However, the original algorithm to select m´ relays from m relays will need to compute C( m, m´ )times, which has high complexity. In this paper, two lower complexity relay selection algorithms are proposed based on maximization of channel capacity for two-hop large scale non-regenerative relay system under the constraint of energy consumption. The simulation results show that the proposed two algorithms not only have almost the same channel capacity but have the lower computational complexity to the original algorithm when the selected relay nodes are same. These two algorithms also perform better than the way of random selection and direct transmission in channel capacity.