基于DAB的自组织数字广播通信网关键技术研究与实现

Although modern public communication systems are powerful, they are easy to be blocked or corrupted in emergency conditions. Broadcast has the advantages of wider coverage and higher reliability, but it can only delivery messages unidirectionally. In this study, by combining the digital audio broadcasting (DAB) and communication technologies, a novel DAB-based self organized network is proposed. DAB in this network is not only radio, but a physical channel to transfer messages. By adding proper dynamic channel allocation and routing algorithms to each DAB transmitter, they are then able to communicate with each other and automatically form a self organized network. As a result, the traditional unidirectional broadcast system turns to a more powerful system with both broadcast and communication functions. The proposed network, which can work independently from the normal communication systems thus provides an emergency communication method when normal communication systems are absent or corrupted, is sure of important scientific significance and social value. This study conducts theoretical analysis to the key technologies of the proposed network, and targets to build a practical prototype network for verification. The research contents involve: 1) optimization of the COFDM encoding algorithm and implementation method, to develop the low-power portable DAB transmitter; 2) research of the dynamic channel allocation and receive-transmit coordinated control algorithm to each DAB transmitter, to implement the bidirectional multimedia communication between two transmitters; 3) research of the receive-metrics-based geographical routing protocol to each DAB transmitter, so that a number of DAB transmitters can form a self organized communication network, in which messages can be transferred to long distance in multi-hops.

现代公共通信系统虽然强大，但紧急时刻易堵塞或损坏。广播覆盖范围广、可靠性高，但只能单向传输信息。本项目将数字广播（DAB）与通信技术相结合，提出基于DAB构建自组织通信网的设想。该网络利用DAB作为传输媒介，通过合理的信道分配和路由机制，使得DAB发射机之间可以双向通信并自动组网，从而将传统的单向广播发展为兼具广播和通信功能的自组织网络。该网络可作为专网独立工作，解决常规通信系统缺乏或瘫痪时的通信问题，具有重要的科学意义和应用价值。本项目对该网络的基本理论和关键技术展开研究，并设计实验网进行验证。研究内容包括：1）DAB的COFDM编码算法和设计方法，以实现低功耗可便携的DAB发射机；2）DAB信道动态分配和收发协同控制算法，以实现两台发射机之间的双向通信；3）基于接收矩阵的地图驱动地理位置路由协议，以实现信息在多台发射机之间的多跳传递，最终形成自配置、自愈、可远程传输的自组织通信网络。

现代公共通信系统虽然强大，但紧急时刻易堵塞或损坏。广播覆盖范围广、可靠性高，但只能单向传输信息。本项目将数字广播（DAB）与通信技术相结合，提出基于DAB构建自组织通信网（DBCN）的设想。通过合理的信道分配和路由机制，使得DAB发射机之间可以双向通信并自动组网，从而将传统的单向广播发展为兼具广播和通信功能的自组织网络，解决常规通信系统缺乏或瘫痪时的通信问题。. 为实现上述目标，开展了如下方面的研究：1）DAB的COFDM编码算法和设计方法，以实现低功耗可便携的DAB发射机；2）DAB信道动态分配和收发协同控制算法，以实现两台发射机之间的双向通信；3）DBCN的路由协议及组网方法研究，以实现信息在多台发射机之间的多跳传递，实现自组织通信。. 主要研究结果及其科学意义概述如下。1）通过优化算法，并采用基于SOPC构架的VLSI设计方法，实现了全部COFDM编码电路在单颗低成本FPGA芯片上的集成，完成了高集成度DAB发射机的设计，整体电路只有18.8*15.5*1.8 cm3，具有集成度高、成本低、可重构的优点，对于加速广播的数字化以及可重构SDR发射机的设计具有重要的参考意义。2）完成了面向双向通信的DAB信道动态分配、收发协同控制算法的研究，实现了DAB发射机的双向多媒体通信。在此基础上，开展了DBCN路由机制和网络构建方法的研究，实现了多台DAB发射机的自组织多媒体通信。DBCN拓宽了数字广播的研究领域，改变了广播的传统形态，使得广播作为传输媒介可以提供独立于移动通信和互联网的专用数据通路，在常规通信系统缺乏或瘫痪的地方，能够自动组网，解决通信问题。