基于变长观察法载波同步的OQPSK全数字解调器  

An All-Digital OQPSK Demodulator Based on Carrier Synchronization Technique of the Method of Dynamical Observation Interval

作　　者：陈振骐[1] 曹志刚[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《电讯技术》2005年第2期111-115,共5页Telecommunication Engineering

摘　　要：在应用于非协同通信的自适应盲接收机系统中,OQPSK信号的解调是一个难点。本文通过对数字同步技术的研究,提出了一种新的OQPSK全数字解调器。该解调器能够在恶劣信号条件下对OQPSK信号进行解调,对Eb/N0、载波频偏、时钟偏差等有很大的宽容度。本文在解调器数字锁相环的研究中提出了“变长观察法”,很好地解决了数字锁相环频率捕捉范围和相位稳定度对观察长度不同要求之间的矛盾,从而显著扩大了低Eb/N0 条件下数字锁相环的频率捕捉范围。In an adaptive blind receiver used in noncooperative communication, the demodulation of the OQPSK signal is a main difficulty. Based on the study of digital synchronization techniques, this paper proposes a new all-digital demodulator for OQPSK. This demodulator can demodulate OQPSK signal in coarse conditions and has large tolerance on the signal conditions of E_b/N_0, the frequency error of the carrier, the phase error of the carrier and the clock. In the research of the phase locked loop (PLL) of the demodulator, this paper develops a novel algorithm named as the method of dynamical observation interval which conquers the contradiction of different requirements of the observation interval between the frequency lock-in range and the loop stability, and then notably increases the frequency lock-in range of the system in the low E_b/N_0 signal condition.

关 键 词：非协调通信系 OQPSK 自适应盲接收机 全数字解调器 信号同步技术 变长观察法 

分 类 号：TN763[电子电信—电路与系统]