一种低SNR下APSK载波相位盲同步方法  

APSK Blind Carrier Phase Synchronization Under Low SNR

作　　者：汪春霆[1] 沈业兵[2] 王爱华[2] 

机构地区：[1]西安电子科技大学通信工程学院,陕西西安710071 [2]北京理工大学信息与电子学院,北京100081

出　　处：《北京理工大学学报》2010年第11期1336-1339,1354,共5页Transactions of Beijing Institute of Technology

基　　金：国家"八六三"计划项目(2009AA01Z232)

摘　　要：提出了一种工作在低信噪比(SNR)条件下,由最小均方误差(MMSE)鉴相和数字二阶闭环组成的幅相键控(APSK)载波相位盲同步方法.给出了载波相位同步环路的参数、采样速率匹配方法及其定点优化实现方案.与盲同步中常见的判决引导算法相比,MMSE鉴相算法无需符号硬判决,对符号误判不敏感,因此具有更大的鉴相范围,降低了相位模糊的重数;运算量虽较大,但可以采用查表法克服这一缺点.A blind carrier synchronization scheme based on minimum mean square error （MMSE） phase error detector and digital 2nd order loop is proposed for the demodulation of APSK in a low-SNR environment. In contrast to the existing decision-directed （DD） algorithm, which is widely adopted for blind synchronization, MMSE phase error detector does not involve the hard symbol decision mechanism, thus it is not sensitive to the false judgment of symbol. Obviously, the detection range is broadened and the degree of phase ambiguity is decreased. To reduce the computational overhead of MMSE detector, a look-up table methodology is used in the scheme. Implementation considerations concerning the key parameters of the carrier phase synchronization loop, the sample-rate adaptive strategy and the fixed point design are summarized.

关 键 词：MMSE鉴相器 载波相位同步 同步环路 

分 类 号：TN914[电子电信—通信与信息系统]