认知MIMO频谱共享系统中基于感知的预编码优化

提出了一种基于时域频谱感知的空域频谱共享策略:先对主用户频谱进行时域感知,如果主用户不存在则立刻进行认知通信,否则根据感知结果调整波束方向和发射功率,以尽量减小对主用户的干扰。具体地,以预编码矩阵为优化参数,最小化次用户均方误差为优化目标,在对主用户的干扰功率约束下,得到了最优的预编码策略。此外,还分别研究了硬判决和软判决对预编码优化的影响。仿真结果表明,基于感知的频谱共享获得的符号均方误差小于传统的频谱共享策略;而基于软判决的频谱共享策略优于基于硬判决的策略。

Sensing based precoding optimization in cognitive MIMO spectrum sharing system

This paper proposed a spatial spectrum sharing strategy based on temporal spectrum sensing. It performed the spectrum sensing first in time domain; the secondary communication could start immediately if the primary user was not presented. Otherwise, it needed regulate the beam direction and transmit power to reduce the possible interference to the primary users. Specifically, it formulated the optimization problem to minimize the MSE of the secondary link with optimal precoding matrix, subject to the interference constraint of the primary users. In addition, it studied the impact of sensing result with hard decision and soft decision on precoding optimization. The simulation result shows that the MSE performance of the proposed strategy based on sensing is superior to the conventional strategy; besides, the spectrum sharing method with soft sensing surpasses the one with hard decision.