Design of High-precision Integrated Communication and Navigation Signal Based on Parasitic Broadcast Signal

Under strong electromagnetic interference and satellite navigation denial scenarios, all types of satellite navigation terminals are unable to function normally. Medium-wave broadcasting is rich in resources, with strong stability of signal propagation by ground wave, which can be used as an important carrier of ground-based navigation system. However, how to effectively embed navigation messages into broadcast signal without interfering with normal service while maintaining positioning accuracy remains a challenge. In this paper, we propose an effective parasitic method for navigation information based on full-hopping multivariate position phase shift keying (MPPSK) modulation, which utilizes MPPSK signals modulated with navigation messages to replace the broadcast carrier for composite modulation. Compared with traditional BPSK, this signal has extremely narrow bandwidth and obvious advantages in coherent demodulation at low signal-to-noise ratio (SNR). Simulation results show that the -50 dB bandwidth of the signal is less than 9 kHz, which meets the requirement of transmit bandwidth, and the coherent cumulative preprocessing-based scheme can effectively improve the signal delay estimation and demodulation performance. Three medium-wave broadcasting stations in Puyang, Shangqiu and Kaifeng are transformed and tested in the field, and the results show that the root mean square error (RMSE) of the positioning of the three stations is within 50 meters. The research results can provide an important theoretical foundation and technical support for China's far-area new-quality covert and trusted navigation and localization, and help to promote the research and application of navigation and localization under satellite navigation denial scenarios.