利用分级正交幅度调制的无线视频传输方法  

Unequal error protection strategy for video transmission over wireless channels with hierarchical QAM

作　　者：李鹏[1] 卢朝阳[1] 常义林[1] 冯妮娜[1] 李志斌[1] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2011年第3期42-47,共6页Journal of Xidian University

基　　金：国家自然科学基金资助项目(60772134;60902081;60902052);高等学校学科创新引智计划资助项目(B08038);西安电子科技大学基本科研业务费资助项目(72105457)

摘　　要：针对带宽有限的多载波无线视频传输,提出了一种利用分级正交幅度调制(HierarchicalQuadrature Amplitude Modulation,HQAM)为视频码流中重要性不同部分提供不等保护的无线视频传输方法.首先将所有可用子载波根据其信道质量划分成不同的类型;其次推导出HQAM调制参数、QAM符号不同位置比特误码率和平均信噪比之间的关系,并为不同类型的子载波分别确定HQAM调制参数;最后将视频码流中对恢复视频质量重要性不等的部分,采用所确定的HQAM调制参数分别调制到对应的子载波上,实现不等保护传输.仿真结果表明,与现有的方法相比,在相同信道带宽和平均信噪比条件下,本方法有效提高了解码端的恢复视频的质量,最高可达2 dB.For band-limited wireless video transmission with multi-subcarriers, a novel unequal error protection strategy for video transmission over the wireless channel by using hierarchical quadrature amplitude modulation （HQAM） is proposed. Firstly, all the subcarriers available are divided into different classes based on their channel quality, and then the HQAM modulation parameters are determined according to the channel quality of those subearriers and the importance of different parts of the video bitstream to the reconstructed video. The unequal error protection of the video bitstream is implemented by modulating different parts in the video stream to subearriers with unequal HQAM parameters. Experimental results demonstrate that compared with the reported methods, the proposed method effectively improves the quality of the reconstructed video with the maximum improvement of about 2 dB.

关 键 词：分级正交幅度调制 不等保护 视频传输 正交频分复用 

分 类 号：TN919.8[电子电信—通信与信息系统]