【摘要】 提出了一种传输小波SPIHT编码图像的联合信源信道编码方法 .该方法针对SPIHT编码码流重要性的不同而进行不同程度的保护 ,并利用无线信道的时变特性自适应地调整信源和信道编码速率 ,从而在不增加额外带宽的前提下有效地提高了系统的性能和可靠性 .在瑞利信道和GE信道下的仿真表明本方法与前文献中提出的EEP方法以及UEP方法相比 ,在信道条件恶劣的情况下 ,能够明显提高恢复图像的质量 .该方案尤其适用于较大范围内的信噪比波动信道更多还原

【Abstract】 Reliable transmission of multimedia services over wireless channel is the key problem for 3G mobile communication. This paper proposes a joint source channel coding scheme based on SPIHT used to transmit progressive image over wireless channel. The method provides unequal protection for SPIHT bit stream with different importance, and adaptively adjusts the source and channel coding rates according to the time varying characteristic of wireless channel, thus yields good performance and high reliability without adding extra bandwidth. Simulations in Rayleigh and Gilbert Elliot channel show that the scheme can obviously improve the image quality compared to EEP and UEP scheme proposed previously, especially when the channel is in bad condition. So the scheme can be applied to fluctuant channel with large range.更多还原