接收功率受限下的信道容量研究

基于频谱共享模型，应用拉格朗日极值定理和注水算法，得出在频谱共享中接收功率 受限的情况下对称信道感知和非对称信道感知下认知用户信道容量的关系式，并分析了主 用户个数对认知用户信道容量的影响。仿真结果表明在相同平均信噪比下，瑞利衰落信道的 信道容量最大，而信噪比越小差别越明显。

Research on channel capacity under received-power constraint condition

Based on the spectrum sharing model and via the Lagrange maximum theory and injection method, the cognitive user channel capacity of the sy mmetric channel and asymmetric channel is calculated respectively under the cond ition that the received power is constrained. The influence of primary user number on the chan nel capacity is analysed. The simulation results show that Rayleigh f ading channel has the most largest capacity under the same average signal-to-noi se ratio(SNR), while the difference will be more obvious when the SNR is smaller.