全双工放大转发中继系统自干扰消除方案研究

发布时间：2018-01-01 07:01

本文关键词：全双工放大转发中继系统自干扰消除方案研究　出处：《南京邮电大学》2016年硕士论文　论文类型：学位论文

【摘要】：未来通信中频谱永远是最稀缺的资源,如何提高现有频谱资源的利用率是通信技术发展必须研究的关键问题。传统的半双工中继(HDR,Half-duplex Relay)系统由于其传送信号在两个不同的时隙,因而其频谱效率低无法满足未来通信的需求。作为下一代移动通信的关键技术,全双工中继(FDR,Full-duplex relay)系统凭借其频率复用特点而受到广泛关注,然而FDR并没有得到应用因为其同时同频收发信号的特性会产生严重的环路自干扰信号。针对FDR系统自干扰消除(SIC,Self-interference Cancellation)这一核心问题,本文主要在模拟域和数字域采取措施消除FDR自干扰,以降低自干扰信号功率,提高系统容量。具体包括:(1)以SISO全双工中继系统为基本模型,分析比较不同自干扰消除能力的全双工放大转发(FD-AF,Full-Duplex Amplify-and-Forward)中继系统与HDR系统的性能。仿真结果表明,自干扰消除能力越强,FD-AF中继系统比HDR系统的性能优势更加明显。(2)基于MIMO全双工中继系统模型,以信道容量为目标函数,以发射功率和信噪比为约束条件,通过构建、求解两个优化问题来得到全双工中继吞吐量最大化的最优中继变换矩阵以抵消自干扰信号的影响,仿真结果表明在相同平均传输功率和信噪比条件下,在最优中继变换矩阵条件下的全双工中继系统相对于半双工中继系统性能优势明显。(3)将模拟域和数字域自干扰消除功能相结合,建立具有多发射单接收天线的FD-AF中继系统模型。以源端到目的端的频谱效率为目标函数,以中继平均传输功率为约束条件,建立最优化模型,通过在一个封闭的算法表达式计算出如何分配传输功率,从而最大化提高系统吞吐量和消除中继系统的自干扰。仿真结果表明,即使考虑到中继接收端射频链路的硬件限制,最优FD-AF的性能也显著优于半双工放大转发中继器(HD-AF,Half-Duplex Amplify-and-Forward)。
[Abstract]:The spectrum will always be the scarcest resource in the future communication. How to improve the efficiency of the existing spectrum resources is the key problem that must be studied in the development of communication technology. Traditional half-duplex relay HDR. The Half-duplex Relay) system transmits signals in two different time slots. Therefore, its low spectrum efficiency can not meet the needs of future communications. As the key technology of the next generation mobile communication, full-duplex relay FDR. Full-duplex relay-based systems have attracted wide attention due to their characteristics of frequency reuse. However, FDR has not been applied because of its simultaneous characteristics of the same frequency transceiver signal will produce a serious loop self-interference signal. For FDR system self-interference cancellation / sic. In this paper, we mainly take measures to eliminate FDR self-interference in analog domain and digital domain. In order to reduce the power of the self-interference signal and improve the system capacity, including 1: 1) the SISO full-duplex relay system is taken as the basic model. The FD-AF of full-duplex amplification and forwarding with different self-interference cancellation capability is analyzed and compared. The performance of Full-Duplex Amplify-and-Forward-based relay system and HDR system. The simulation results show that the stronger the self-interference cancellation ability is. The performance advantage of FD-AF relay system is more obvious than that of HDR system. (2) based on the MIMO full-duplex relay system model, the channel capacity is taken as the objective function, and the transmit power and signal-to-noise ratio (SNR) are taken as the constraint conditions. By constructing and solving two optimization problems, the optimal relay transformation matrix for maximizing the throughput of full-duplex relay is obtained to counteract the influence of self-interference signal. The simulation results show that under the same average transmission power and signal-to-noise ratio conditions. The full-duplex relay system under the optimal relay transformation matrix has obvious performance advantages over the half-duplex relay system, which combines the analog domain with the digital domain self-interference cancellation function. The FD-AF relay system model with multiple transmit single receiving antennas is established. The optimal model is established with the spectral efficiency from the source to the destination as the objective function and the average transmission power of the relay as the constraint condition. Through a closed algorithm expression, how to allocate transmission power is calculated to maximize system throughput and eliminate self-interference of relay system. The simulation results show that. Even considering the hardware constraints of the RF link at the receiving end of the relay, the performance of the optimal FD-AF is significantly better than that of the half-duplex amplifier repeater (HD-AF). Half-Duplex Amplify-and-Forward.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN92

【相似文献】