Abstract

Cognitive radio systems are intelligent communication systems that can be established on the fly in difficult ter-rains. The prime features of the cognitive radio systems are adaptive carrier frequency, adjustable power and ef-fective spectrum utilization. The entire system consists of nodes. The distance between the nodes becomes cru-cial for the communication process. The selection of relays becomes a bottle neck while the communication needs to be established between distant nodes. In this paper, a new relay selection scheme (NRSS) is implement-ed by the fuzzy logic for double hop cooperative transmission. With this proposed technique the user can increase the performance of the cooperative node. The requirements which are needed in the relay selection schemes are SNR (signal to noise ratio), cooperative gain and the gain of the channel are some of the parameters observed in fuzzy input for getting the best relay.

Key words: Optimal selection approach, fuzzy logic, SNR ratio, MIMO-CR, Relay selection, NRSS.