软件无线电中π/4-DQPSK突发信号位定时算法

A Symbol Timing Acquisition Algorithm for Burst-Mode π/4-DQPSK in Software Radio Systems

阐述了一种新的适合于软件无线电的π/4-DQPSK突发信号的码元定时恢复、频偏估计和纠正方法。这种算法根据π/4-DQPSK本身特点,对信号能量检测、频移初捕实行并行处理,这与常规算法中的先信号能量检测,再估计多普勒频移,然后进行位定时捕获的串行处理相比,有较明显的优越性。该算法具有简单、计算量小和易于用DSP实现的特点,因此适合在软件无线电接收机中使用。

This paper elaborates a new method for symbol timing recovery, frequency offset estimation and correction of burst-mode π/4 -DQPSK in software radios. This algorithm, by employing which signal acquisition and frequency offset acquisition can be performed in parallel, has advantages over serial systems, which detect signal energy, then estimate Doppler frequency offset, and finely acquire symbol timing. Due to its simplicity, low calculation requirement and easy realization in DSP, the method is readily implemented in software radio receivers. The results of computer simulations and software design are given.