Cooperative Diversity in Cognitive Relay Networks Using Different Coding Techniques
Cognitive Radios (CR) represent new technique that can effectively improve the spectrum efficiency of future wireless networks. In this paper, the problem of cooperative relay in CR networks will be investigated for further improve network performance. A scenario in which a secondary transmitter can communicate with a secondary receiver via a direct communication link or a relay channel will be considered. Cooperative relay communications or cooperative diversity has emerged as a promising technique to combat fading in wireless communications. Two well-known cooperative diversity are known as Decode-And-Forward (DAF) and Amplify-And-Forward (AAF). In this paper, the DAF strategy will be considered, which achieves diversity by using Maximal Ratio Combining (MRC) and Fixed Ratio Combining (FRC).