Abstract: In cognitive radio system, the efficiency of spectrum handoff is always a challenge. To conquer this difficulty, classification and matching scheme is adopted. The users are classified according to their type of services at first, and then a reliable channel evaluation is designed to match the classifications of the users. This spectrum handoff scheme based on classification and matching is efficient when the users’ number is large. Simulation results show that the proposed algorithm is a viable method of prompting spectrum handoff efficiency, and reducing congestion probability, handoff number and handoff delay.

Key words: cognitive radio, spectrum handoff, channel ranking, handoff delay

摘要： 针对认知无线电系统中，频谱切换效率低这个难点，采用分组匹配的思想，基于业务类型对用户进行分组，将用户分组与一种全面可靠的信道评估机制匹配。这种先分组后分配信道的切换算法能有效提高多个用户的复杂场景中频谱切换的效率。仿真结果表明，该算法能够减少认知用户拥塞概率、频谱切换次数以及切换延迟，提高频谱切换效率，有效保证系统服务质量。

关键词: 认知无线电, 频谱切换, 信道排序, 切换延迟