多径信道下图像的信源信道联合编码调制传输

Image transmission over multipath fading channel using joint source channel coding modulation

针对多径衰落信道提出了一种基于小波变换并结合OFDM(Orthogonal Fre-quency Division Multiplexing)自适应调制的图像传输方法和信源信道联合带宽功率优化分配算法.给出了编码传输方法结构,对有噪信道下基于小波变换的图像编码传输实现和失真估计问题及多误码率OFDM自适应调制比特功率优化分配问题进行了建模和分析,使得信源量化编码与OFDM调制能够方便地结合起来,并进一步得到了相应的信源信道联合优化带宽功率分配方法.仿真和分析表明,该方法实现了多径信道下图像的信源信道联合编码调制传输,编解码复杂度和延迟小,且信源信道联合优化的带宽功率分配可有效提高信道资源利用效率.

For multipath fading channel,an image transmission method which combines wavelet transform and orthogonal frequency division multiplexing（OFDM） adaptive modulation was proposed,and the algorithm for joint source channel optimal allocation of channel bandwidth and power was presented as well.Following the presentation of system structure,the problems such as the implementation and distortion estimation of image transmission based on wavelet transform over noisy channel,and optimal bit-power allocation for multi bit error rate（BER） OFDM adaptive modulation were modeled and analyzed,modeling and analysis facilitate the combination of source quantization coding and OFDM adaptive modulation,and a joint source channel optimal bandwidth and power allocating algorithm was also developed.Simulations and analysis show that the image transmission using joint source-channel coding modulation over multipath fading channel can be achieved with small coding complexity and delay,and performance can be improved due to joint source-channel optimal allocation of bandwidth and power.