Abstract: Two algorithms using Orthogonal Frequency Division Multiplexing(OFDM) are proposed after reviewing research on spectrum allocation in multiuser Cognitive Radio(CR). The optimal algorithm obtains the total transmission power through the lower limit of primary users’ Signal to Interference Ratio(SIR), and allots every user subcarriers and power according to Lagrange’s theorem. The hypo-optimal algorithm uses a prorating gene to determine equity of allocation. Results are obtained through restricting the users’ SIR. Simulations results show both algorithms are effective compared with Frequency Division Multiple Access(FDMA) allocation, and satisfy the needs of CR.

Key words: Cognitive Radio(CR), Orthogonal Frequency Division Multiplexing(OFDM), spectrum allocation, channel capacity, Signal to Interference Ratio(SIR), cognitive user

摘要： 结合正交频分复用(OFDM)技术，研究认知无线电场景中的多用户频谱分配策略，提出最优与次优2种算法。最优算法通过授权用户的SIR下限得到认知无线电的发射总功率，采用拉格朗日定理为每个认知用户分配子载波和功率。次优算法引入分配比例因子来体现用户分配的公平原则，通过限制SIR得到频谱分配结果。仿真结果表明，2种算法的性能优于现有基于FDMA的静态频谱分配算法，能从不同层面满足认知无线电的需求。

关键词: 认知无线电, 正交频分复用, 频谱分配, 信道容量, 信噪比, 认知用户

CLC Number: 

• TN925.93