Seamless spectrum handover improving cell outage in cognitive radio systems

In cognitive radio systems, there is a concern of service disruption because of spectrum handover. Spectrum handover occurs when a secondary user changes frequency due to the appearance of a primary user. Spectrum handover can be frequent if a cognitive radio system operates in a wide spectrum band. In this case, spectrum handover may drastically degrade the performance of cognitive radio systems because of the different propagation loss according to the usage of different frequency. Here, we propose a seamless spectrum handover scheme. The proposed handover scheme can avoid service disruption and can reduce redundant handovers. The efficiency of the proposed scheme is validated by simulation results.