VoIP Capacity Analysis in Cognitive Radio System with Single/Multiple Channels

In this letter, the voice over IP (VoIP) capacity in Cognitive Radio system is studied with single and multiple channels. A special Cognitive Radio (CR) system is used, the Cognitive radio system adopt the frequency of near 700 M Hz, a wireless channel can be modeled as a two-dimensional discrete-time Markov chain. The traffic of a single VoIP user is described as a Markov modulated Poison process (MMPP). Two kinds of systems is considered: single-channel system-in which VoIP data will be transmitted in a single channel; multi-channels system-VoIP data will be transmitted in several channels together, performance of both of the systems will be simulated in our CR system, and give a comparison. We obtained the packet dropping probability and the average throughput, after analysis these results, we give the conclusion.