Analysis of the Influence of the Channel Model on the Optimum Switching Points in a Cognitive Radio Network Using Adaptive FEC

This work investigates the performance of a network that combines cognitive radio and the adaptive forward error correction technique, where access to the medium is done opportunistically by secondary users. The power metric is used to analyze the influence of the Nakagami-m fading channel model in determining the ideal switching points of an adaptive forward error correction scheme. In the adopted scenario, primary and secondary users are modeled using M / G / 1 queues, with priority access to the channel for the primary user. Theoretically, spectral sensing is perfect in ways that mutual interference between users was not considered. The transmission system allows two packet retransmission scenarios: without limits and with a limited number of retransmissions of packets received in error. The results show that the optimal switching points vary with the fading order and the current error correction code.