水声网络多跳中继策略与动态编码协作技术研究

项目名称： 水声网络多跳中继策略与动态编码协作技术研究

项目编号： No.41476026

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 陈友淦

作者单位： 厦门大学

项目金额： 98万元

中文摘要： 多跳和中继可为水声网络提供更有利的带宽资源、有效降低路径损耗,是极具发展潜力的下一代高速水声通信与网络解决方案。通过编码实现协作通信的编码协作技术,可同时获得编码增益和分集增益。如何从编码协作角度，研究适合水声信道的多跳中继策略，是当前协作多跳水声网络亟待解决的关键问题。 项目在多跳水声网络中结合码率兼容码(如RC-LDPC)技术,首次提出重复冗余(RR)和额外冗余(ER)两种OFDM调制的动态编码协作（DCC）中继策略,协作节点根据信道的动态条件成功解码后立即向接收端发送RR/ER数据，接收端将其叠加到来自信源的原始数据进行联合解码，可提高链路可靠性;若需启动ARQ重传,则只需从协作节点动态重传一小部分冗余数据,可有效降低端到端传输时延，克服水声信道大时延的不利影响。还将研究协作节点的时延控制策略，精确实现各节点间的同步通信,以及双层RC-LDPC码,利用节点间信息互递特性降低误码率。

中文关键词： 水声通信；水声网络；信号处理

英文摘要： Multi-hop and relay strategies could offer more favorable bandwidth and path loss conditions, and appear as an attractive solution for providing high-rate services for the next-generation underwater acoustic (UWA) communication and networks. Also coded cooperation could obtain both coding gain and spatial diversity gain. To address challenges posed by UWA channels, there are still many problems demanding prompt solution in exploring the best multi-hop and relay strategies for cooperative multi-hop UWA networks via coded cooperation. In this project, we proposed tow OFDM modulated dynamic coded cooperation (DCC) schemes, termed repetition redundancy (RR) and extra redundancy (ER), for multi-hop UWA networks based on rate compatible codes (e.g., RC-LDPC codes). The cooperative node switches to cooperation phase, transmitting RR/ER data to the receiver, immediately after it decodes the message. Then the receiver will do joint decoding via superimposing the cooperative data and the original data collecting from the source node, which provides a more reliable cooperative path for the specific network. Further, if the ARQ mechanism works, the cooperative node only needs to retransmit parts of the packet, in which a reduced end-to-end transmission latency can be achieved. Additionally, the OFDM block-level synchronization was carried out by proposing a delay control mechanism at the cooperative node, and two layered RC-LDPC code was used for inter- and intra-block encoding to reduce the bit error rate.

英文关键词： Underwater Acoustic Communications;Underwater Acoustic Networks;Signal Processing