分布式波束成形载波同步策略

Methods for Carrier Synchronization of Distributed Transmit Beamforming

分布式波束成形是协作通信的一种形式,其中两个或多个信源节点同时传输同一个信息并控制其相位,目的端重组接收信号。载波偏移使得终端的信号重组产生偏差,严重影响通信质量。分析了载波同步对分布式波束成形的重要性,介绍了现有的分布式波束成形中的载波同步策略。频率同步的方法是主-辅结构同步,相位同步有开环相位同步和闭环相位同步两个方法。分布式载波同步后传输信号在目标节点有效地重组整合,增加了分布式波束成形技术的可行性。

Distributed transmit beamforming is a form of cooperative communication in which two or more information sources simultaneously transmit a common message and control the phase of their transmissions so that the signals combine at an intended destination. Cartier frequency offset will significantly degrade the performance of communication by damaging the combine at the destination. It proved that the carrier synchronization is the significant problem for distributed transmit beamforming and introduced some existing methods for carrier synchronization of distributed transmit beamforming that can reduce the effect of the carrier. One approach to frequency synchronization is to employ a master-slave architecture. There are two basic approaches to phase synchronization, closed-loop phase synchronization and open-loop phase synchronization. After distributed carrier synchronization, the transmissions combine constructively at the destination. That makes the feasibility of distributed transmit beamforming increases.