多普勒频移修正下的快速伪码捕获技术的实现
|
摘要
快速准确地实现伪码捕获是扩频通信研究的关键。在实际应用中,通常会存在噪声干扰和多普勒效应的影响,导致捕获难度变大。传统的串行捕获或并行捕获法存在捕获时间长、低信噪比环境下难以实现捕获或难以克服多普勒效应的影响等。详细研究了多普勒频移对伪码捕获的影响,利用FFT的算法进行伪码捕获,并对多普勒频移进行修正,通过仿真,证明了此种方法可以在低信噪比和较大多普勒效应下准确地实现伪码的快速捕获。
Fast and accurate pseudo-code acquisition is the key technology of spread spectrum communication research.In practical application,there are usually interference from noise and doppler effect,which make acquisition more difficult.Traditional serial acquisition or parallel acquisition methods have some disadvantages,such as long acquisition time,difficult acquisition under low signal-to-noise ratio(SNR)environment,or difficult to overcome the influence of doppler effect.In this paper,the influence of doppler frequency shift on pseudo-code acquisition is studied in detail.The algorithm of FFT is used to capture pseudo-code,and to correct the doppler frequency shift.The simulation results show that this method can accurately achieve the fast acquisition of pseudo-code under low SNR and more doppler effect.
Fast and accurate pseudo-code acquisition is the key technology of spread spectrum communication research.In practical application,there are usually interference from noise and doppler effect,which make acquisition more difficult.Traditional serial acquisition or parallel acquisition methods have some disadvantages,such as long acquisition time,difficult acquisition under low signal-to-noise ratio(SNR)environment,or difficult to overcome the influence of doppler effect.In this paper,the influence of doppler frequency shift on pseudo-code acquisition is studied in detail.The algorithm of FFT is used to capture pseudo-code,and to correct the doppler frequency shift.The simulation results show that this method can accurately achieve the fast acquisition of pseudo-code under low SNR and more doppler effect.
引文
[1]吴资玉,韩庆文,蒋阳.通信原理[M].北京:电子工业出版社,2008.
[2]Polydoros A,Weber C.A unified approach to serial search spread-spectrum code acquisition part I/II:a matched-filter receiver[J].IEEE transactions on communications,1984,32(5):550-560.
[3]Chawla K K,Sarwate D V.Parallel acquisition of PN sequences in DSSS systems[J].IEEE trans on Commun,1994,42(5):2155-2164.
[4]Yu TS.Rapid code acquisition algorithms employing PN matched filters[J].IEEE trans on Commun,1998,36(6):724-733.
[5]Akopian D.Fast FFT based GPS satellite acquisition methods[J].IEEE proceedings-rada,sonar and navigation,2005,152(4):277-286.
[6]邬志影,常青,尚梦云.基于FFT的二维并行长码捕获算法[J].太赫兹科学与电子信息学报,2015,(13)5:758-760.
[7]高玉平.一种基于FFT的多普勒扩频信号捕获方法[J].无线电工程,2016,46(1):39-41.
[8]梁保卫,涂海洋.大多普勒条件下伪码捕获技术[J].专题技术与工程应用,2014,44(8):86-88.
[9]张静静.高动态下扩频系统的同步技术研究[D].南京:南京理工大学,2009.
[10]王学运,张升康,王海峰,等.基于FFT的伪码捕获技术研究与实现[J].电子测量技术,2014,37(2):1-4.
[2]Polydoros A,Weber C.A unified approach to serial search spread-spectrum code acquisition part I/II:a matched-filter receiver[J].IEEE transactions on communications,1984,32(5):550-560.
[3]Chawla K K,Sarwate D V.Parallel acquisition of PN sequences in DSSS systems[J].IEEE trans on Commun,1994,42(5):2155-2164.
[4]Yu TS.Rapid code acquisition algorithms employing PN matched filters[J].IEEE trans on Commun,1998,36(6):724-733.
[5]Akopian D.Fast FFT based GPS satellite acquisition methods[J].IEEE proceedings-rada,sonar and navigation,2005,152(4):277-286.
[6]邬志影,常青,尚梦云.基于FFT的二维并行长码捕获算法[J].太赫兹科学与电子信息学报,2015,(13)5:758-760.
[7]高玉平.一种基于FFT的多普勒扩频信号捕获方法[J].无线电工程,2016,46(1):39-41.
[8]梁保卫,涂海洋.大多普勒条件下伪码捕获技术[J].专题技术与工程应用,2014,44(8):86-88.
[9]张静静.高动态下扩频系统的同步技术研究[D].南京:南京理工大学,2009.
[10]王学运,张升康,王海峰,等.基于FFT的伪码捕获技术研究与实现[J].电子测量技术,2014,37(2):1-4.