基于Zadoff-Chu序列的OFDM精确定时同步算法
|
摘要
针对OFDM系统在多径衰落环境下通过能量大小定时而产生定时误差的问题,文中提出了一种基于Zadoff-Chu序列的第一径检测算法,利用序列相关性得到信道冲激响应估计值,此外分析了残留频偏对定时同步的影响,并通过改进自适应门限抑制残留频偏来判定准确定时位置。算法在时域完成,实现简单且运算量小。通过仿真对比其他算法可以看出,文中所提算法在高速移动多径环境中第一径检测概率高、均方误差小,特别是低信噪比下仍能准确同步。
This paper proposed a first path detection algorithm based on Zadoff-Chu sequence in order to solve timing error caused by OFDM system in multipath channel. The correlation property of Zadoff-Chu sequence is utilized to estimate the channel impulse response. In addition,the influence of residual frequency offset on timing synchronization is analyzed,and the accurate timing position is determined by improving the adaptive threshold and suppressing the residual frequency offset. The algorithm is completed in the time domain,which is simple to implement and small in computation. Analysis and simulation results show that the proposed algorithm has high probability of detection and low mean squared error in high-speed moving multipath environment,and at low signal-to-noise ratio.
This paper proposed a first path detection algorithm based on Zadoff-Chu sequence in order to solve timing error caused by OFDM system in multipath channel. The correlation property of Zadoff-Chu sequence is utilized to estimate the channel impulse response. In addition,the influence of residual frequency offset on timing synchronization is analyzed,and the accurate timing position is determined by improving the adaptive threshold and suppressing the residual frequency offset. The algorithm is completed in the time domain,which is simple to implement and small in computation. Analysis and simulation results show that the proposed algorithm has high probability of detection and low mean squared error in high-speed moving multipath environment,and at low signal-to-noise ratio.
引文
[1] Cui T,Zhou Q,Li J,et al. The analysis and research of adaptive transmission algorithms in wireless communication system[C].IEEE International Conference on Communication Problem-Solving.IEEE,2016:615-618.
[2] Wang W J,Tian Y,Ahn C J. Blind symbol timing synchronization scheme for real-time industrial wireless control network using highspeed preambleless OFDM systems over multipath fading channels[J]. Digital Signal Processing,2017,62:30-37.
[3]Panda M,Mishra S. Performance analysis of concomitant synchronization algorithms for OFDM and non-contiguous OFDM systems[C]. International Conference on Man and Machine Interfacing.IEEE,2018.
[4]Schmidl T M,Cox D C. Robust frequency and-timing synchronization for OFDM[J]. IEEE Transactions on Communications,1997,45(12):1613-1621.
[5] Minn H,Zeng M,Bhargava V K. On timing offset estimation for OFDM systems[J]. IEEE Communications Letters,2000,4(7):242-244.
[6]Park B,Cheon H,Kang C,et al. A novel timing estimation method for OFDM systems[J]. IEEE Communications Letters,2003,7(5):239-241.
[7]Fang Y,Zhang Z,Liu G. A Novel Synchronization Algorithm Based on CAZAC Sequence for OFDM Systems[C]. International Conference on Wireless Communications,NETWORKING and Mobile Computing. IEEE,2012:1-4.
[8]Kishore C N,Reddy V. A technique for dominant path delay estimation in an OFDM system and its application to frame synchronization in OFDM mode of WMAN[J]. EURASIP Journal on Wireless Communications and Networking,2006(2):1-8.
[9]张洁,蔡鹏,张平.一种适用于多径衰落信道的OFDM定时同步算法[J].北京邮电大学学报,2005,28(2):105-108.
[10]刘彬,罗志年,彭疆.改进CAZAC序列的OFDM时频同步算法[J].计算机工程与应用,2017,53(14):76-79,98.
[11]Das A,Mohanty B,Sahu B. A Novel CAZAC Sequence Based Timing Synchronization Scheme for OFDM System[J]. International Journal of Advances in Applied Sciences,2018,7(1):66-72.
[12]Yang F,Zhang X. Robust Time-Domain Fine Symbol Synchronization for OFDM-Based Packet Transmission Using CAZAC Preamble[C]. 2013 IEEE Military Communications Conference(MILCOM2013). San Diego,2013:436-440.
[13] Blumenstein J,Bobula M. Coarse Time Synchronization Utilizing Symmetric Properties of Zadoff-Chu Sequences[J]. IEEE Communications Letters,2018(99):1.
[14]Gul M M U,Ma X,Lee S. Timing and Frequency Synchronization for OFDM Downlink Transmissions Using Zadoff-Chu Sequences[J]. IEEE Transactions on Wireless Communications,2015,14(3):1716-1729.
[15]吴玉成,陈婷婷.在滑动窗口中判决的自适应门限检测方法[J].系统仿真学报,2008,20(10):2770-2773.
[16] Huang H,Wang W G J,He J. Phase noise and frequency offset compensation in high frequency MIMO-OFDM system[C]. IEEE International Conference on Communications. IEEE,2015:1280-1285.
[2] Wang W J,Tian Y,Ahn C J. Blind symbol timing synchronization scheme for real-time industrial wireless control network using highspeed preambleless OFDM systems over multipath fading channels[J]. Digital Signal Processing,2017,62:30-37.
[3]Panda M,Mishra S. Performance analysis of concomitant synchronization algorithms for OFDM and non-contiguous OFDM systems[C]. International Conference on Man and Machine Interfacing.IEEE,2018.
[4]Schmidl T M,Cox D C. Robust frequency and-timing synchronization for OFDM[J]. IEEE Transactions on Communications,1997,45(12):1613-1621.
[5] Minn H,Zeng M,Bhargava V K. On timing offset estimation for OFDM systems[J]. IEEE Communications Letters,2000,4(7):242-244.
[6]Park B,Cheon H,Kang C,et al. A novel timing estimation method for OFDM systems[J]. IEEE Communications Letters,2003,7(5):239-241.
[7]Fang Y,Zhang Z,Liu G. A Novel Synchronization Algorithm Based on CAZAC Sequence for OFDM Systems[C]. International Conference on Wireless Communications,NETWORKING and Mobile Computing. IEEE,2012:1-4.
[8]Kishore C N,Reddy V. A technique for dominant path delay estimation in an OFDM system and its application to frame synchronization in OFDM mode of WMAN[J]. EURASIP Journal on Wireless Communications and Networking,2006(2):1-8.
[9]张洁,蔡鹏,张平.一种适用于多径衰落信道的OFDM定时同步算法[J].北京邮电大学学报,2005,28(2):105-108.
[10]刘彬,罗志年,彭疆.改进CAZAC序列的OFDM时频同步算法[J].计算机工程与应用,2017,53(14):76-79,98.
[11]Das A,Mohanty B,Sahu B. A Novel CAZAC Sequence Based Timing Synchronization Scheme for OFDM System[J]. International Journal of Advances in Applied Sciences,2018,7(1):66-72.
[12]Yang F,Zhang X. Robust Time-Domain Fine Symbol Synchronization for OFDM-Based Packet Transmission Using CAZAC Preamble[C]. 2013 IEEE Military Communications Conference(MILCOM2013). San Diego,2013:436-440.
[13] Blumenstein J,Bobula M. Coarse Time Synchronization Utilizing Symmetric Properties of Zadoff-Chu Sequences[J]. IEEE Communications Letters,2018(99):1.
[14]Gul M M U,Ma X,Lee S. Timing and Frequency Synchronization for OFDM Downlink Transmissions Using Zadoff-Chu Sequences[J]. IEEE Transactions on Wireless Communications,2015,14(3):1716-1729.
[15]吴玉成,陈婷婷.在滑动窗口中判决的自适应门限检测方法[J].系统仿真学报,2008,20(10):2770-2773.
[16] Huang H,Wang W G J,He J. Phase noise and frequency offset compensation in high frequency MIMO-OFDM system[C]. IEEE International Conference on Communications. IEEE,2015:1280-1285.