零中频接收机直流偏移消除技术及FPGA实现
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摘要
针对零中频接收机的直流偏移问题,提出一种利用改进卡尔曼滤波器进行直流偏移消除的新方法。在高斯信道以及瑞利衰落信道下,采用标准dPMR协议基带信号进行Matlab仿真,得到最优的卡尔曼滤波器参数,并给出相应的FPGA电路结构。分析了应用该方法后接收信号的眼图和估计误差均方差等性能。仿真结果表明,该方法能有效地减小直流偏移对系统性能的影响。与传统的模拟方法相比,该方法不需要额外的补偿电路,减少了电路面积。与传统的数字统计算法相比,该方法所需的估计点数减少了90%。
A new DC offset compensation(DCOC) method based on an improved Kalman filter was proposed to solve the problem of DC offset in zero-IF receiver. In the Gaussian channels and Rayleigh fading channels, the baseband system of standard dPMR protocol was simulated with Matlab to obtain the optimal Kalman filter parameters, and the corresponding FPGA circuit structure was given. The eye diagrams of the received signals and the mean square errors of the estimation results were analyzed. The simulation results showed that the proposed method could effectively reduce the influence of DC offset on the system performance. Compared with the traditional analog method, the proposed method didn't need additional compensation circuits, which reduced the circuit area. Compared with the traditional digital statistical algorithm, the proposed method had reduced the number of estimated point by 90%.
A new DC offset compensation(DCOC) method based on an improved Kalman filter was proposed to solve the problem of DC offset in zero-IF receiver. In the Gaussian channels and Rayleigh fading channels, the baseband system of standard dPMR protocol was simulated with Matlab to obtain the optimal Kalman filter parameters, and the corresponding FPGA circuit structure was given. The eye diagrams of the received signals and the mean square errors of the estimation results were analyzed. The simulation results showed that the proposed method could effectively reduce the influence of DC offset on the system performance. Compared with the traditional analog method, the proposed method didn't need additional compensation circuits, which reduced the circuit area. Compared with the traditional digital statistical algorithm, the proposed method had reduced the number of estimated point by 90%.
引文
[1] 童游.零中频接收机中数字自动增益控制和直流失配补偿电路的设计 [D].南京:东南大学,2017.
[2] TANG D,WANG J,PENG Z,et al.A DC-coupled biomedical radar sensor with analog DC offset calibration circuit [C] // IEEE Int Instru & Measure Technol Conf.Houston,TX,USA.2018:1-6.
[3] FAN X L,SUN Y T,FENG Y Y.An efficient CMOS DC offset cancellation circuit for PGA of low IF wireless receivers [C] // Int Conf Wireless Commun & Signal Process.Suzhou,China.2010:1-5.
[4] SAPENOV Y,CHAABAN A,REZKI Z,et al.Optical MISO IM/DD channels:optimality of spatial repetition codes among DC-offset STBCs [C] // IEEE Int Symp Inform Theo.Aachen,Germany.2017:71-75.
[5] 袁伟娜,王平.基于ZCZ训练序列的MIMO-DDST联合信道与直流偏移估计 [J].铁道学报,2012,34(8):52-56.
[6] 柯璟.直接转换接收机的IQ失配和直流偏移补偿研究 [D].南京:南京理工大学,2011.
[7] NIHEI S,UMEHIRA M,TAKEDA S.A modified DFTs-OFDM with DC subcarrier shift for low PAPR and DC offset error robustness [C] // IEEE 81st Technol Conf.Glasgow,UK.2015:1-6.
[8] 徐礼哲.消除零中频接收机直流偏移的分析和研究 [J].电子技术,2010,47(9):45-46,43.
[9] 唐琴,吴建辉.零中频直流偏移消除技术比较与分析 [J].微电子学,2008,38(6):811-816.
[10] GUO H Z,WANG L.The design of radio modem based on standard dPMR [J].Microcomput App,2014,30(8):1-3,7.
[2] TANG D,WANG J,PENG Z,et al.A DC-coupled biomedical radar sensor with analog DC offset calibration circuit [C] // IEEE Int Instru & Measure Technol Conf.Houston,TX,USA.2018:1-6.
[3] FAN X L,SUN Y T,FENG Y Y.An efficient CMOS DC offset cancellation circuit for PGA of low IF wireless receivers [C] // Int Conf Wireless Commun & Signal Process.Suzhou,China.2010:1-5.
[4] SAPENOV Y,CHAABAN A,REZKI Z,et al.Optical MISO IM/DD channels:optimality of spatial repetition codes among DC-offset STBCs [C] // IEEE Int Symp Inform Theo.Aachen,Germany.2017:71-75.
[5] 袁伟娜,王平.基于ZCZ训练序列的MIMO-DDST联合信道与直流偏移估计 [J].铁道学报,2012,34(8):52-56.
[6] 柯璟.直接转换接收机的IQ失配和直流偏移补偿研究 [D].南京:南京理工大学,2011.
[7] NIHEI S,UMEHIRA M,TAKEDA S.A modified DFTs-OFDM with DC subcarrier shift for low PAPR and DC offset error robustness [C] // IEEE 81st Technol Conf.Glasgow,UK.2015:1-6.
[8] 徐礼哲.消除零中频接收机直流偏移的分析和研究 [J].电子技术,2010,47(9):45-46,43.
[9] 唐琴,吴建辉.零中频直流偏移消除技术比较与分析 [J].微电子学,2008,38(6):811-816.
[10] GUO H Z,WANG L.The design of radio modem based on standard dPMR [J].Microcomput App,2014,30(8):1-3,7.