J4 ›› 2013, Vol. 40 ›› Issue (4): 14-20+101.doi: 10.3969/j.issn.1001-2400.2013.04.003

• 研究论文 • 上一篇    下一篇

导频和软信息联合辅助的短突发SOQPSK载波同步

孙锦华1;朱吉利1;吴小钧2   

  1. (1. 西安电子科技大学 综合业务网理论及关键技术国家重点实验室,陕西 西安  710071;
    2. 长安大学 信息工程学院,西安 710064)
  • 收稿日期:2012-03-15 出版日期:2013-08-20 发布日期:2013-10-10
  • 通讯作者: 孙锦华
  • 作者简介:孙锦华(1979-),女,副教授,博士,E-mail: jhsun@xidian.edu.cn.
  • 基金资助:

    国家自然科学基金资助项目(60902039, 61271175);中央高校基本科研业务费专项资金资助项目(K50511010014,K5051201043,CHD2011JC088);长安大学基础研究支持计划

Joint pilot and soft information assisted carrier synchronization for short burst SOQPSK signals

SUN Jinhua1;ZHU Jili1;WU Xiaojun2   

  1. (1. State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China;
    2. School of Information Engineering, Chang'an University, Xi'an 710064, China)
  • Received:2012-03-15 Online:2013-08-20 Published:2013-10-10
  • Contact: SUN Jinhua

摘要:

针对采用成形偏移QPSK(SOQPSK)调制的短帧突发通信系统在大频偏条件下的载波恢复问题,提出了一种导频和解调软信息联合辅助的载波同步算法.该算法首先利用少量的导频序列进行载波偏差粗估计,然后在粗估计值附近的一定区间内进一步细搜索,以SOQPSK解调软信息均方值最大化为准则,得到精确的载波估计值.仿真结果表明,在信噪比大于0dB、导频序列长度为30bit时,该算法能够以较低的运算复杂度校正小于符号速率一半的载波频偏,克服相位模糊,实现有效的载波同步,获得接近最佳相干解调的误比特性能.在误比特率为10-2~10-5时,信噪比损失在0.3dB以内.

关键词: SOQPSK, 导频, 软信息, 载波同步

Abstract:

To solve the carrier recovery problem with large frequency offset in short burst communication systems using shaped-offset quadrature phase shift keying(SOQPSK), a joint pilot and demodulation soft information assisted carrier synchronization algorithm is proposed. First, coarse synchronization based on a few short pilot sequences is carried out. Then, further fine search is done around the coarse synchronization estimation region. The precise carrier synchronization parameters are obtained based on the maximum-mean-square soft output of SOQPSK. Simulation results show that at Eb/N0≥0dB the proposed algorithm can eliminate large carrier offsets by as much as half the symbol rate, resist phase confusion and achieve effective carrier synchronization with 30 pilot bits and low computation complexity, achieving a BER performance which is very near the optimal coherent demodulation performance. When BER is in the region of 10-2~10-5, SNR degradation is below 0.3dB.

Key words: SOQPSK, pilot, soft information, carrier synchronization

中图分类号: 

  • TN911.3