提出一种适合于零前缀正交频分复用(ZP—OFDM)系统的符号盲同步方法.该方法基于ZP—OFDM符号中的ZP功率出现规律性的分布特性,利用滑动窗能量检测的办法进行符号同步.另外,研究了高斯信道和瑞利多径信道下的符号同步方法,详细推导了瑞利多径信道下接收信号的功率分布特性,得出了统一的表达式,进而得出了在多径环境下该方法及其性能与估计窗口宽度的关系;同时,为了提高同步性能,设计了多滑动窗方法代替双滑动窗方法.计算机仿真分析表明,无论高斯信道下还是瑞利多径信道下,该方法都具有优异的性能.
A low-complexity blind symbol-timing synchronization scheme applicable to zero prefix-orthogonal frequency-division multiplexing(ZP-OFDM )systems is presented. The proposed method is based on zero prefix(ZP) power collection in the ZP-OFDM symbols whose ZP average power distribute regularly in the slide windows. The synchronization schemes in both Gauss channel and multipath Rayleigh fading channel are investigated. Average power distribution of the received signal in multipath Rayleigh fading channel is analysed in detail in order that symbol synchronizes accurately. The relation of synchronization performance and the window's width is presented. A multi-slide-windows method is designed in order to improve the performance of synchronization. Final computer results also demonstrate the superior performance of the new method in both Gauss channel and multipath Rayleigh fading channel.