振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2015年
17期
38-43
,共6页
LFM-BPSK 复合调制%参数估计%L-DFT%Alpha 稳定分布噪声
LFM-BPSK 複閤調製%參數估計%L-DFT%Alpha 穩定分佈譟聲
LFM-BPSK 복합조제%삼수고계%L-DFT%Alpha 은정분포조성
LFM-BPSK combined modulation%parameter estimation%L-DFT%Alpha stable noise
针对现有的复合调制信号参数估计方法在 Alpha 稳定分布噪声中性能严重退化的问题，提出一种基于L-DFT（L-Filter-Based DFT）的线性调频与相位编码（Linear Frequency Modulation and Binary Phase Shift Keying，LFM-BPSK）复合调制信号参数估计方法。该方法首先定义了 L-DCFT（L-Filter Based Discrete Chirp-Fourier Transform），平方倍频法消除编码调相后，采用 L-DCFT 估计信号的起始频率和调制斜率；分析了循环自相关函数中脉冲出现概率增大的问题，提出了基于改进 L-DFT 和循环统计量的码速率估计方法。仿真结果表明，基于 L-DFT 的参数估计方法能有效抑制脉冲噪声，在强脉冲噪声中具有良好的参数估计性能。
針對現有的複閤調製信號參數估計方法在 Alpha 穩定分佈譟聲中性能嚴重退化的問題，提齣一種基于L-DFT（L-Filter-Based DFT）的線性調頻與相位編碼（Linear Frequency Modulation and Binary Phase Shift Keying，LFM-BPSK）複閤調製信號參數估計方法。該方法首先定義瞭 L-DCFT（L-Filter Based Discrete Chirp-Fourier Transform），平方倍頻法消除編碼調相後，採用 L-DCFT 估計信號的起始頻率和調製斜率；分析瞭循環自相關函數中脈遲齣現概率增大的問題，提齣瞭基于改進 L-DFT 和循環統計量的碼速率估計方法。倣真結果錶明，基于 L-DFT 的參數估計方法能有效抑製脈遲譟聲，在彊脈遲譟聲中具有良好的參數估計性能。
침대현유적복합조제신호삼수고계방법재 Alpha 은정분포조성중성능엄중퇴화적문제，제출일충기우L-DFT（L-Filter-Based DFT）적선성조빈여상위편마（Linear Frequency Modulation and Binary Phase Shift Keying，LFM-BPSK）복합조제신호삼수고계방법。해방법수선정의료 L-DCFT（L-Filter Based Discrete Chirp-Fourier Transform），평방배빈법소제편마조상후，채용 L-DCFT 고계신호적기시빈솔화조제사솔；분석료순배자상관함수중맥충출현개솔증대적문제，제출료기우개진 L-DFT 화순배통계량적마속솔고계방법。방진결과표명，기우 L-DFT 적삼수고계방법능유효억제맥충조성，재강맥충조성중구유량호적삼수고계성능。
In order to solve the problem that the existing parameter estimation algorithm for hybrid modulated signals significantly degrades under Alpha stable noise,an L-DFT (L-Filter-Based DFT)based algorithm for hybrid modulated signals with binary phase shift keying (BPSK)and linear frequency modulation (LFM)parameter estimation is proposed.Firstly,the definition of L-DCFT (L-Filter Based Discrete Chirp-Fourier Transformation)is given.Then,the square frequency doubling method is applied to eliminate the binary phase modulation of the reconstructed signals,the initial frequency and chirp rate are estimated with L-DCFT.The problem of the probability growth of pulses in cyclic autocorrelation is analyzed,and a symbol rate estimation algorithm based on the modified L-DFT and cyclic statistics is proposed.Simulation results show that the L-DFT based method can suppress impulse noise efficiently and it has a superior parametric estimation performance under heavier impulse noise.
