分布式无速率码在深空通信中的应用研究
发布时间：2018-10-22 14:30
【摘要】：随着人类探索宇宙的进度的加快,人类能触及的宇宙范围越来越广泛,深空通信的通信双方距离遥远,由于宇宙中的噪声特性不同于常规的无线通信系统,信道模型很复杂,同时深空通信是典型的资源受限系统,其设备功率和重量等资源有限,因此深空通信相对于地面通信系统有其独特性。遥远的距离使得反馈的差错控制成为不可能,为了满足深空通信的需求,M.Luby等提出了喷泉码数据传输技术。喷泉码是一种无速率删除码,在数据包长度很长时有着很好的性能,编码过程中它持续地产生编码数据包,根据对通信环境的评估合理的调节发送的编码数据包的数量,当目的节点接收到比发送数据包数量稍多的编码数据包后即可以很高的概率译码成功。它的编译码算法复杂度很低,是一种不需要反馈就能保证通信的可靠性的低复杂度数据传输机制,而且经过改进的LT码在多信源单中继的模型中性能更卓越。本论文从深空通信的背景出发,详细介绍了深空通信的信道特点和喷泉码编译码原理,根据喷泉码的编码特点对喷泉码进行了仿真,并从深空通信的网络模型中提取出网络中比较简单常见的多信源单中继通信模型。再从两信源单中继通信模型出发,通过对鲁棒孤波分布解卷积对分布式LT码展开算法研究和性能仿真,得出分布式LT码的传输策略要比LT码数据传输策略更为高效,比分开传输数据节省了一定量的数据包。再者,考虑到通信中通常会有数据的优先级的不同,针对这一实际情况,对LT码的编码机制进行改进对重要的数据包进行更加高效可靠的传输,并对其性能进行仿真验证,在此基础上将分级保护算法应用到多信源单中继模型中去,得到分布式分级保护LT码,仿真表明其性能比分布式LT码要更好。最后从分级保护中可知LT码的度分布其实是有很大的改进空间,因此提出几种不同于鲁棒孤波分布的度分布,并对其性能进行仿真,在SF-LT码的基础上,对其对分布进行解卷积并将之应用到分布式深空通信模型中去,最后得到具有卓越性能的分布式SF-LT码。
[Abstract]:With the acceleration of human exploration of the universe, the scope of the universe can be reached more and more widely, and the distance between the two sides of the deep space communication is far away. Because of the noise characteristics in the universe is different from the conventional wireless communication system, the channel model is very complex. At the same time, deep space communication is a typical resource-limited system, and its equipment power and weight are limited, so deep space communication is unique to terrestrial communication system. In order to meet the requirement of deep space communication, M.Luby and others put forward the fountain code data transmission technology because of the long distance which makes the feedback error control impossible. Fountain code is a rateless delete code, which has good performance when the packet length is very long. During the coding process, it continuously produces encoded data packets, and adjusts the number of encoded packets according to the evaluation of the communication environment. When the destination node receives a bit more encoded packets than the number of transmitted packets, it can decode successfully with a high probability. Its complexity is very low, and it is a low complexity data transmission mechanism which can guarantee the reliability of communication without feedback. Moreover, the improved LT code has better performance in the model of multi-source and single-relay. Based on the background of deep space communication, this paper introduces the channel characteristics of deep space communication and the encoding and decoding principle of fountain code in detail, and simulates fountain code according to the coding characteristics of fountain code. The simple and common multi-source single-relay communication model is extracted from the network model of deep space communication. Based on the two-source single-relay communication model, through the research of robust solitary wave deconvolution algorithm and performance simulation of distributed LT code, it is concluded that the transmission strategy of distributed LT code is more efficient than that of LT code data transmission strategy. Than separate transmission of data to save a certain amount of data packets. Furthermore, considering the different priority of data in communication, the coding mechanism of LT code is improved to transmit the important data packets more efficiently and reliably, and its performance is verified by simulation. On this basis, the hierarchical protection algorithm is applied to the multi-source single-relay model, and the distributed hierarchical protection LT code is obtained. The simulation results show that its performance is better than that of the distributed LT code. Finally, the degree distribution of LT code is found to have great improvement space from the hierarchical protection. Therefore, several degree distributions which are different from the robust solitary wave distribution are proposed, and their performance is simulated. Based on the SF-LT code, the degree distribution of the code is simulated. The distribution is deconvolution and applied to the distributed deep space communication model. Finally, the distributed SF-LT codes with excellent performance are obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927
本文编号：2287426
[Abstract]:With the acceleration of human exploration of the universe, the scope of the universe can be reached more and more widely, and the distance between the two sides of the deep space communication is far away. Because of the noise characteristics in the universe is different from the conventional wireless communication system, the channel model is very complex. At the same time, deep space communication is a typical resource-limited system, and its equipment power and weight are limited, so deep space communication is unique to terrestrial communication system. In order to meet the requirement of deep space communication, M.Luby and others put forward the fountain code data transmission technology because of the long distance which makes the feedback error control impossible. Fountain code is a rateless delete code, which has good performance when the packet length is very long. During the coding process, it continuously produces encoded data packets, and adjusts the number of encoded packets according to the evaluation of the communication environment. When the destination node receives a bit more encoded packets than the number of transmitted packets, it can decode successfully with a high probability. Its complexity is very low, and it is a low complexity data transmission mechanism which can guarantee the reliability of communication without feedback. Moreover, the improved LT code has better performance in the model of multi-source and single-relay. Based on the background of deep space communication, this paper introduces the channel characteristics of deep space communication and the encoding and decoding principle of fountain code in detail, and simulates fountain code according to the coding characteristics of fountain code. The simple and common multi-source single-relay communication model is extracted from the network model of deep space communication. Based on the two-source single-relay communication model, through the research of robust solitary wave deconvolution algorithm and performance simulation of distributed LT code, it is concluded that the transmission strategy of distributed LT code is more efficient than that of LT code data transmission strategy. Than separate transmission of data to save a certain amount of data packets. Furthermore, considering the different priority of data in communication, the coding mechanism of LT code is improved to transmit the important data packets more efficiently and reliably, and its performance is verified by simulation. On this basis, the hierarchical protection algorithm is applied to the multi-source single-relay model, and the distributed hierarchical protection LT code is obtained. The simulation results show that its performance is better than that of the distributed LT code. Finally, the degree distribution of LT code is found to have great improvement space from the hierarchical protection. Therefore, several degree distributions which are different from the robust solitary wave distribution are proposed, and their performance is simulated. Based on the SF-LT code, the degree distribution of the code is simulated. The distribution is deconvolution and applied to the distributed deep space communication model. Finally, the distributed SF-LT codes with excellent performance are obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927
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1 姚文顶;李晖;陈立甲;许洪光;;深空通信中喷泉码技术研究[J];系统工程与电子技术;2009年01期
相关硕士学位论文 前1条
1 任祥维;适用于深空通信的编码调制算法和实现研究[D];电子科技大学;2011年
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