On joint source-channel decoding for correlated sources
On joint source-channel decoding for correlated sources
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相关源的联合源通道解码
DOI：
10.1109/icassp.2002.5745156
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
P. Vary
中科院分区：
文献类型：
--
作者：
M. Adrat;Roland Haenel;P. Vary
每当数字通信受到延迟和复杂性的限制时，在源编码之后就会保留一些剩余冗余。香农分离定理并不严格成立，因此联合源通道解码是有益的。在本文中，我们讨论了两种利用（自）相关方面的剩余冗余的竞争方法。将分析两者对量化噪声和信道失真的影响。第一种方法利用接收器处的冗余来估计源编解码器参数的最小均方误差。第二种方法通过预测编码来利用发射机处的相关性。预测增益可以降低量化噪声或比特率。备用比特率可用于特定的错误保护，从而减少信道失真。但除此之外，接收机处可利用较少的冗余来进行参数估计。模拟将表明，预测编码方案提高了各种信道条件下的质量，但与香农分离定理相反，在接收机侧利用相关性在非常恶劣的信道条件下是有益的。
Whenever digital communications is subject to constraints in delay and complexity, some residual redundancy remains after source coding. Shannon's separation theorem does not hold strictly and hence joint source-channel decoding is beneficial. In this paper we discuss two competing approaches exploiting residual redundancy in terms of (auto)-correlation. Both will be analyzed with respect to their impact on quantization noise and channel distortion. The first approach exploits redundancy at the receiver for minimum mean squared error estimation of source codec parameters. The second approach exploits correlation at the transmitter by predictive encoding. The prediction gain allows to reduce quantization noise or bitrate. The spare bitrate can be used for specific error protection and hence reduction of channel distortion. But otherwise, less redundancy is utilizable at the receiver for parameter estimation. Simulations will show that the predictive encoding scheme improves quality in a wide range of channel conditions, but in contrast to Shannon's separation theorem the utilization of correlation at the receiver side is beneficial in very bad channel conditions.