基于TDS-OFDM系统的发射分集技术  

Transmitter diversity scheme for TDS-OFDM

作　　者：王劲涛[1] 潘长勇[1] 杨知行 

机构地区：[1]清华大学电子工程系微波与数字通信技术国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2006年第1期58-62,共5页Journal of Tsinghua University(Science and Technology)

摘　　要：为了提高在衰落信道下数字电视地面广播系统的传输性能,在时域同步正交频分复用(TDS-OFDM)系统中应用空时、空频两种发射分集方法。根据系统信号帧结构的特点,提出了简单易行的发射链路信号配置方法,保持原有链路不变,运算复杂度小。同时,分析了空时、空频两种分集方法的适用范围。仿真结果表明:在慢衰落信道下,两种方法都能提高系统的误码性能,当误码率为10-3时有不低于8dB的分集增益;在快衰落信道下,空时分集性能受D opp ler频移的影响而变得很差,空频分集的增益则与在慢衰落信道时相近。对于不同类型的信道采用合适的发射分集方法,数字电视地面广播系统的传输性能可以得到很大提高。Space-time and space-frequency transmitter diversity schemes were developed to improve the transmission performance of digital television terrestrial broadcasting （DTTB） over fading channels, Simple transmitted signal configurations were constructed based on the frame structure of the time domain synchronous - orthogonal frequency division multiplexing （TDS-OFDM） system, The original transmission branch is maintained and the computations are greatly simple. Simulations show that the two methods both improve the BER performance over slow fading channels. At the threshold of αRER = 10^-3, the diversity gain exceeds 8dB. Over fast fading channels, the space-time diversity becomes very bad because of the Doppler shift, while the space-frequency diversity gain is similar to that over slow fading channels, Therefore, the transmission performance of DTTB can be greatly improved by choosing the transmitter diversity scheme according to the channel characteristics.

关 键 词：电视数字技术 数字电视地面广播 时域同步正交频分复用 地面数字多媒体/电视广播协议 空时发射分集 空频发射分集 

分 类 号：TN941.3[电子电信—信号与信息处理]