摘要
为了提高带宽效率和信息的传输质量,提出了一种高阶调制下基于低密度奇偶校验码(LDPC)的信源信道联合编码方法。根据格雷(Gray)映射下高阶调制符号中不同比特的抗噪声性能差异,将调制符号中各比特等效成一组并行比特子信道,结合多级树集合分裂(SPIHT)算法编码后图像码流的特点,利用密度进化方法优化LDPC码的度分布。为了提高对图像重要信息的保护,利用非规则LDPC码的非均等保护特性,重新分配图像码流数据。实验结果表明,该方法能够较大提高无线通信图像传输的可靠性和有效性。
In order to improve the bandwidth efficiency and information transmission quality,a joint source-channel coding method based on LDPC codes is proposed for high order modulation.According to the anti-noise performance of different bits of high order mod-ulation symbols under Gray mapping,the modulation symbols in each bit is equivalent to a set of parallel bit subchannels,combined with the characteristics of image code stream after using SPIHT algorithm for coding,the density evolution method is used to optimize the degree distribution of LDPC codes.In order to improve the protection of the important image information,the UEP characteristics of irregular LDPC codes is used for re-allocation of the stream data of image.The experiments show that the method can greatly improve the reliability and availability of wireless image transmission.
出处
《无线电工程》
2015年第11期21-25,共5页
Radio Engineering
基金
国家自然科学基金资助项目(61371186
61461015
61261032
61162007)
广西自然基金项目(2013GXNSFFA019004
2014GXNSFAA118399)
广西教育厅重点项目(ZD2014052)
关键词
无线通信
密度进化
高阶调制
非均等保护
wireless communication
density evolution
high order modulation
UEP
