面向无线传感器网络的源-信道-网络联合无线传输理论研究

压缩感知(CS)、LDPC码和网络编码(NC)技术是三个性能优良的现代信号处理技术，它们的共同特点是通过一个转换矩阵实现了从一个空间到另一个空间的几何映射。虽然有文献初步研究了CS与LDPC之间的关系和基于LDPC技术的网络编码，但是就如何将这三种技术有机地融合在一起，则是一个全新的课题，其不仅要求要有统一的转换矩阵，而且要有统一的译码算法和性能度量准则。课题通过探索无线传感器网络的稀疏特性，充分利用WSN感知信号的空、时相关特性，研究CS和LDPC技术之间的相互转换关系和基于LDPC技术的高分集增益网络编码方案，建立以LDPC技术为纽带、面向无线传感器网络的联合源-信道-网络无线传输方案，即CS-LDPC-NC方案，并对其性能进行分析。该方案不仅具有较高的能量效率、较高的频谱效率和接近香浓容限的特征，而且易于实现。为探索CS、LDPC和NC技术之间的本质联系及其在WSN中的应用奠定理论基

In modern signal processing techniques, there are three techniques with good performance, which are compressed sensor (CS), low-density parity-check (LDPC), and network coding (NC). By using CS and NC techniques, the energy efficiency and spectral efficiency of the systems can be greatly improved, respectively. At the same time, LPDC technique has the capacity to approach theoretical capacity limits. The common characteristic of the three techniques are that the signals are transformed from a space to another by using transform matrixes. It is an open issue how to perfectly integrate the three techniques, though the relationship among CS, LDPC, and NC has been explored in literatures. This requires not only the uniform transform matrix among the three techniques, but also the uniform decoding (or signal recovery) algorithms and the measurement criterions for good performance. By using the sparsity of the sensing signals of the wireless sensor networks (WSN), the relationship between the CS and LDPC techniques will be investigated firstly. Secondly, with the consideration of high diversity gain and the using of LDPC, the network coding schemes will be presented as well as the corresponding decoding algorithms. Finally, with LDPC technique as a link, a joint source-channel-network coding scheme will be presented as well as the corresponding performance analysis for wireless sensor networks, which is referred to as CS-LDPC-NC scheme, in which the three techniques are integrated together perfectly. The scheme not only combines the merits of the three techniques, but also makes it possible to implement in engineering. The study will provide the science basis for the development of wireless sensor network and the exploration of the relationship between CS, LDPC, and NC.