论文部分内容阅读
本文主要在认知系统下研究最优功率分配问题,其中主用户和非主用户共享同一频谱资源。在本系统中主用户基于多天线技术,而非主用户基于MIMO-OFDM技术。利用信道感知技术可以使非主用户首先监听主用户的传输信息,其次估计从主用户到非主用户的正交空间。不同于之前的关于MIMO认知系统中信道感知技术的研究,本文首次把OFDM技术引入MIMO认知系统中并在本系统中考虑非理想信道估计问题。然而由于信道估计误差,估计信道和实际信道之间有误差,使得从非主用户到主用户终端的干扰没有完全消除。然后本文提出了一种有效的算法,使得我们得到了在保证主用户Qo S下最大化非主用户吞吐量的最优的功率分配。仿真结果描述了非主用户的发射功率约束和主用户的干扰功率约束以及非主用户的吞吐量之间的影响。
This paper mainly studies the optimal power allocation problem under the cognitive system, in which the primary user and the non-primary user share the same spectrum resource. The main user in this system is based on multi-antenna technology, rather than the main user based on MIMO-OFDM technology. The use of channel-sensing technology allows non-primary users to monitor the primary user’s transmission information first, and secondly to estimate the primary user to the non-primary user’s orthogonal space. Different from previous researches on channel sensing technology in MIMO cognitive system, this paper introduces OFDM technology into MIMO cognitive system for the first time and considers non-ideal channel estimation in this system. However, due to the channel estimation error, there is an error between the estimated channel and the actual channel, so that the interference from the non-primary user to the primary user terminal is not completely eliminated. Then, we propose an efficient algorithm that allows us to obtain the optimal power allocation that maximizes the throughput of non-primary users while ensuring the primary user QoS. The simulation results describe the impact of the non-primary user’s transmit power constraint and the primary user’s interference power constraints and the throughput of non-primary users.