Analysis of effect of distance of relay node in cooperative communication

In the context of ad-hoc networks and wireless sensor networks the concept of cooperative communication through relays have significant advantage. It decreases the signal degradation that occurs because of factors such as signal multi path-propagation and fading. Cooperative diversity uses a multiple antenna environment to improve or maximize total network channel capacities for any given set of bandwidths. This is done by exploiting user diversity by decoding the combined signal from the relay and the source of the information in wireless multi-hop networks. There are several relaying strategies to implement cooperative diversity, and some of the basic strategies are Amplify-and-Forward, Decode-and-Forward and Compress- and Forward. Each of them have their own advantage and they can provide different performance results with different environment. Variation of probability of error can be seen with the change in signal combining strategy.