广域、低成本的导航增强覆盖是进一步实质性改善北斗导航系统精度和可用性的重要途径。在本项目中，我们提出一种共生调频数据广播导航增强技术，即利用共生于现有模拟调频广播带内的数据广播进行北斗差分、导航辅助和伪卫星增强。然而，带内的共生数据广播导航增强信号受调频信号的强干扰难以解调，在复杂无线电应用环境下如何实现对共生数据广播导航增强信号的充分利用也是不小的技术挑战。针对上述难点，本项目从“共生调频数据广播系统的模拟和数字信号共生”以及“复杂无线电应用环境下共生数据广播导航增强信号的充分导航利用”两个方面进行研究，争取突破利用共生调频数据广播进行导航增强的基础理论和部分关键技术。本项目的共生调频数据广播导航增强技术具有广域、低成本、信号连续的技术特点，是一项具备良好前景的北斗导航增强方案。

Wide area yet low cost navigation enhancement is the key to substantial improvement of BeiDou navigation system precision and availability. In this work, we aim at an innovative BeiDou navigation enhancement by a symbiotic FM in band on channel digital broadcast signal, which can provide differential, aided and pseudolite enhancement to BeiDou. However, it is hard to cancel the strong interference of FM on the symbiotic digital broadcast signal; it is also a challenge to fully explore the symbiotic digital broadcast signal for navigation enhancement under complex wireless environment. Toward the above two aspects, we will mainly study on “the symbiosis of the analog FM and digital broadcast signal” and “full usage of the symbiotic digital broadcast signal for navigation enhancement”. We aim at some theoretical and key technologies break through on navigation enhancement by the symbiotic FM in band on channel digital broadcast signal. The proposed navigation enhancement by symbiotic FM in band on channel digital broadcasting is a promising solution toward a wide area, low cost and public acceptable BeiDou navigation enhancement system.