摘要
介绍了低信噪比调制解调技术的研究背景及其必要性,并指出了低信噪比解调所面临的问题。给出了调制解调器的主要技术参数,并针对低信噪比提出了一种调制解调器的实现方案,该方案采用在发送数据中插入训练序列的方法,来辅助载波恢复和定时恢复,解决了低信噪比解调的难点问题。该调制器解调器结构简单,适于低信噪比的情况。
This paper introduces the research background and necessities of modulation/demodulation technique at low SNR, presents the problems this method faces, gives the main technical parameters of the modem, and aiming at the low SNR problem, puts forward a kind of self-designed modem. The method of inserting a training sequence into transmitted data is used in carrier recovery and timing recovery loops. The difficult problems of demodulation at low SNR are solved. This modem for low SNR has simple structure.
出处
《无线电工程》
2007年第1期51-52,共2页
Radio Engineering
关键词
QPSK
调制解调
捕获
载波恢复
定时恢复
QPSK
modulation/demodulation
acquisition
carrier recovery
timing recovery
