同时同频全双工自干扰抑制关键技术研究与验证

发布时间：2018-01-17 17:27

本文关键词：同时同频全双工自干扰抑制关键技术研究与验证　出处：《电子科技大学》2014年博士论文　论文类型：学位论文

【摘要】：同时同频全双工以相同的时间和相同的频率发送接收信号,与频分双工和时分双工相比,理想情况下最高可获得两倍的频谱利用率,是提高下一代无线和有线通信系统容量的有效措施之一。然而,同时同频全双工的发射信号干扰了远端过来期望信号的检测。如何抑制发射信号对自身接收的这种自干扰,工程实现中有什么挑战?本文针对这些问题进行研究。首先,分析并验证了同时同频全双工的射频自干扰抑制能力。在现实的工程约束条件下,分析了自干扰功率、带宽、幅度调整误差、相位调整误差对自干扰抑制能力影响,给出了闭合解析表达式,并进行了实验测试验证。实验与分析结果表明,在自干扰信号带宽为20MHz、自干扰功率为-10dBm的条件下,当幅度调整误差为0.005dB、相位调整误差为0.05度时,射频自干扰抑制能力达到51.2dB。其次,分析并验证了同时同频全双工的数字自干扰抑制能力。针对频域重建自干扰抑制方法,在自干扰信道为多径瑞丽衰落信道的条件下,分析了自干扰功率、自干扰信道估计误差对数字自干扰抑制能力影响,给出了闭合解析表达式,并进行了实验测试验证。实验与分析结果表明,当自干扰信号带宽为20MHz、干噪比为40dB时,数字自干扰抑制能力达到31.2dB。再次,针对自干扰信道估计误差会恶化数字自干扰抑制能力的问题,提出了一种可变窗长离散傅里叶变换信道估计算法,提高了低干噪比下自干扰信道估计的精度。数值分析和仿真结果表明,在莱斯自干扰信道的条件下,干噪比为15dB时,可变窗长离散傅里叶变换信道估计算法相对于最小二乘信道估计能带来约2.2dB的自干扰抑制能力提升。最后,针对LTE的应用场景,联合射频自干扰抑制和数字自干扰抑制,设计了单发单收LTE同时同频全双工工程样机。分析了LTE同时同频全双工系统对自干扰抑制能力需求,设计了自干扰抑制工程实现方案。工程样机实验测试表明,在自干扰功率为-10dBm的条件下,射频与数字联合自干扰抑制能力达到70dB,LTE同时同频全双工双向数据速率提高了一倍。论文工作为同时同频全双工自干扰抑制技术提供了理论和方法支撑,部分成果得到了工程验证。研究结果可应用于中继系统、军用无线通信系统、无线局域网以及下一代无线和有线通信系统中。
[Abstract]:At the same time, the same frequency full duplex transmits the received signal at the same time and the same frequency. Compared with the frequency division duplex and time division duplex, the highest spectrum efficiency can be obtained in the ideal situation. It is one of the effective measures to improve the capacity of the next generation wireless and wired communication systems. At the same time, the same frequency full-duplex signal interferes with the detection of the expected signal from the far end. How to suppress the self-interference of the transmitted signal to itself, what are the challenges in the engineering implementation? In this paper, these problems are studied. Firstly, the capability of simultaneous full-duplex RF self-interference suppression is analyzed and verified. Under the practical engineering constraints, the self-interference power and bandwidth are analyzed. The effect of amplitude adjustment error and phase adjustment error on the ability of self-interference suppression is discussed. The closed analytical expression is given, and the experimental results are verified. When the self-interference signal bandwidth is 20MHz and the self-interference power is -10dBm, when the amplitude adjustment error is 0.005dB, the phase adjustment error is 0.05 degrees. The radio frequency self-interference suppression ability is 51.2 dB. Secondly, the digital self-interference suppression capability of full-duplex with the same frequency is analyzed and verified. Under the condition that the self-interference channel is a multi-path Rayleigh fading channel, the influence of self-interference power and self-interference channel estimation error on the digital self-interference suppression ability is analyzed, and the closed analytical expression is given. The experimental results show that when the bandwidth of the self-interference signal is 20MHz and the ratio of interference to noise is 40dB, the ability of digital self-interference suppression can reach 31.2 dB. Aiming at the problem that the estimation error of self-interference channel will worsen the ability of digital self-interference suppression, a channel estimation algorithm with variable window length discrete Fourier transform (DFT) is proposed. The accuracy of self-interference channel estimation under low signal-to-noise ratio is improved. Numerical analysis and simulation results show that under the condition of Les self-interference channel, the ratio is 15dB. The variable window length discrete Fourier transform channel estimation algorithm can improve the self-interference suppression ability of about 2.2 dB compared with the least square channel estimation. Finally, the application scenario of LTE is proposed. Combined with RF self-interference suppression and digital self-interference suppression, a single-send and single-receive LTE simultaneous cofrequency full-duplex engineering prototype is designed, and the demand for self-interference suppression capability of LTE simultaneous co-frequency full-duplex system is analyzed. The experimental results show that under the condition of self-interference power of -10 dBm, the combined radio frequency and digital self-interference suppression ability can reach 70 dB. The bidirectional data rate of simultaneous full duplex of LTE is doubled. The work of this paper provides theoretical and methodological support for simultaneous full duplex self-interference suppression. The results can be applied to relay system, military wireless communication system, wireless local area network and the next generation wireless and wired communication system.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5;TP393.01

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