认知多址接入系统中的能量消耗优化研究

考虑认知多址接入系统中的多个次用户与主用户同时共享多个信道的能量消耗问题，次用户能够同时感知和接入多个主用户信道并把对主用户的干扰维持在一定的范围内。为了减少能量消耗，需要对感知时间、信道以及功率进行合理的分配，同时，把干扰功率作为约束条件以保证主用户的服务质量。在基于多用户多信道感知的频谱共享方案中，所建立的初始优化问题为非凸整型组合分式规划问题，为了对感知时间、信道及功率进行联合优化，将其进行凸松弛并进一步转化为一个含参数的线性问题，从而提出一种最小化能量消耗的算法。通过实验仿真讨论次用户数量，信道数量及干扰功率对能量消耗和最优感知时间的影响，同时也验证了分析结果。

Study on optimization of energy consumption in cognitive multiple access system

The energy consumption is considered in cognitive multiple access system, which the channels are simultaneously shared by multiple secondary users and primary users. The multiple channels are sensed and accessed by secondary users at the same time and the interferences on primary users are kept within a certain range. Sensing time, channels and inter ference power are needed to be properly allocated for reducing energy consumption. Moreover, the interference power is served as constraint condition for protecting quality of service of primary users. The constructed initial optimizing problem is the non-convex integer combinatorial fractional programming issues in the multi-users multi-channels sensing-based spectrum sharing scheme. The concave relaxation is used to solve the issues which are further transformed the parametric linear problem for jointly optimizing sensing time, channels and power and an algorithm of minimizing energy consumption is proposed. Finally the impacts of the number of secondary users and channels and interference power on the energy consumption and optimal sensing time are discussed by simulations. Meanwhile the analysis is verified.