摘要
在新的欧洲DAB(数字音频广播)标准基础上提出一种分层调制技术。这种技术可以针对不同优先级的码流采用不同等级的保护,可以应用在分级视频编码中。在物理层应用高阶差分调制的分层调制技术,既可在现有的带宽内提高频谱利用率,又可兼顾组网灵活性和终端的移动性能。以DAB系统物理层为框架,对不同阶数的差分调制以及不同调制因子等参数进行了仿真。给出了误比特率为10-7量级上不同层次的信噪比仿真结果,结果显示高优先级码流平均比低优先级码流有15dB左右的增益。
One hierarchical modulation method based on the DAB system is presented to protect streams according to their priorities, which can be used in scalable video coding. In physical layer, the implementation of hierarchical modulation can improve not only the spectral efficiency but also the terminal mobility and the flexibility of building network. Based on the DAB physical layer structure, simulation is done at different order＇s differential modulation and different modulation level. Different hierarchical layer＇s SNR simulation result at the BER is given, and the result shows that the high priority stream has nearly 15dB gain compared with the low priority stream.
出处
《电子工程师》
2007年第12期22-24,共3页
Electronic Engineer
关键词
数字多媒体广播
DAB
分层调制
digital multimedia broadcasting
DAB
hierarchical modulation
