In cognitive radio systems, spectrum handover occurs when a secondary user changes frequency due to the appearance of a primary user. Spectrum handover may result in degraded system performance because of the different propagation loss of the different frequency. In this case, data transmission is disrupted and it is more difficult to provide seamless service. Here, we propose a seamless handover scheme based on the prediction of cell coverage. The proposed handover scheme can avoid service disruption and can reduce redundant handovers. The efficiency of the scheme is validated by simulation results.