摘要
提出了一种应用于数字电视地面广播(DTTB)的新的编码调制方案.首次以多级分组乘积码代替传统的串行级联编码结构,提高了频谱效率;同时采用一种多分辨率64QAM星座图,可在一个DTTB信道中提供3种级别的服务.在接收端采用基于MAX-LOG-MAP准则的迭代Turbo译码算法以获得可靠接收.仿真结果表明,在视觉门限BER=3×10-6处,高优先级码流的比特信噪比约为7dB,适用于高可靠性的服务.中优先级和低优先级码流可支持室外固定接收.
A new channel coding and modulation scheme adopted in Digital Television Terrestrial Broadcasting (DTTB) is presented, in which multilevel Block Product Code (BPC) is for the first time introduced to replace the serially concatenated coding architectures to improve spectrum efficiency and a multi-resolution 64QAM constellation is used for hierarchical modulation to offer three tiers of services within one DTTB channel. In the receiver, an iterative turbo decoding algorithm based on MAX-LOG-MAP criterion is adopted to achieve robust reception. Simulation shows that the bit SNR of High Priority stream is about 7 dB at the Threshold of Visibility, which is competent for services requiring high reliability. The Medium and Low Priority streams can support fixed outdoor reception.
出处
《北京邮电大学学报》
EI
CAS
CSCD
北大核心
2004年第2期72-76,共5页
Journal of Beijing University of Posts and Telecommunications
基金
高等学校优秀青年教师科研奖励计划资助项目