基带同步调制离散性分析及射频同步应用研究

Research on Performance Analysis of Base-band Synchronization and Comparison with RFST

目前基于多载波调制技术的地面数字电视单频网,采用基带码流分配方式保证数据接收的可靠性,但存在调制离散性,长时延多径等产生的同频干扰问题。而基于射频分发产生的射频同步技术(RFST)为有效解决这些问题提供新的组网方案。通过对现有基带同步的调制离散性分析,得出调制误差率不一致对接收信号误码率的影响结果,并与采用RFST技术的单频网系统方案进行比较。理论推导表明,RFST技术保证各发射站点发射信号频谱特性一致。而仿真结果和实验网测试结果表明,RFST技术有效降低误码率,因此此中、小功率覆盖的方式可为小区域覆盖提供了更优性能的组网方案。

Single Frequency Network （SFN）of territorial digital TV,utilizing multi-carrier modulation,is usually based on baseband TS stream distribution to ensure the data reliability,but it still has problems on modulation discreteness,co-channel interference caused by long delay time.Radio Frequency Synchronization Technology （RFST） can solve these problem based on RF signal distribution.The relationships between modulation discreteness and BERs of base-band synchronization is analyzed and the results to RFST are compared.With results from theoretical derivation,simulink tests and trial project network prove that RFST offers a more excellent networking scheme of the small area coverage for Digital Video Broadcasting-Territorial （DVB-T）,by ensuring the identical spectral characteristics of RF signals from different stations and reducing BER.