认知无线电网络中基于主系统有限反馈的频谱共享方案

Spectrum sharing scheme in cognitive radio networks based on primary limited feedback

提出一种频谱共享方案，该方案适用于同时存在多个主用户和一对次用户的场景。各主用户依据接收机反馈的有限信道质量信息（CQI, channel quality information）分配发送功率及传输速率。次用户根据偷听到的主系统CQI有限反馈，以适当的功率及速率接入信道。次用户接入信道的行为对各主用户造成一定干扰，以致主系统传输速率遭受一定损失。在主系统速率损失约束条件下，得出了使次系统吞吐量最大化的次用户发送功率及传输速率最佳分配方案。数值结果表明，对于每个主用户仅需反馈3~4个量化比特，次系统的有效吞吐量就可堪比于主次发射端均拥有主系统链路完整CQI的情况。仿真结果显示，所提出的频谱共享方案能够满足主系统速率损失约束。

A spectrum sharing scheme for a pair of secondary users co-existing with multiple primary users was proposed. The primary users exploit the limited feedback of channel quality information （CQI） to allocate their transmission power and rate. By overhearing the limited feedback of primary CQI, the secondary user accessed the channel with proper transmission power and rate while causing interference to the primary users and so the rate loss of the primary system. Under the primary rate loss constraint, the optimal transmit power and transmission rate for the secondary was obtained to maximize the secondary user throughput. Numerical results show that, with only 3 or 4 bits of feedback to each prima-ry user, the effective throughput of the secondary system is comparable to the case with both primary and secondary transmitters having the perfect CQI of the primary link. The simulation results demonstrate that the proposed spectrum sharing scheme can meet the primary rate loss constraint.