Design of high-precision ranging and communication composite signal based on UNB

With the increasing shortage of spectrum resources, the demand for high spectrum utilization and high-precision positioning in ranging and communication composite systems is becoming more and more urgent. Aiming at the problems of low spectral efficiency and easy interference in complex environment of traditional system, a design of ranging and communication composite signal based on full-hopping m-ary position phase shift keying (MPPSK) modulation is proposed. Compared with the traditional modulations, the bandwidth of the signal is very narrow and it has obvious advantages in time delay estimation and coherent demodulation at low signal-to-noise ratio. The simulation results show that the signal bandwidth of -60dB is approximately 1kHz and the spectral efficiency is 31.25 bit/s/Hz. Under the low signal-to-noise ratio, the root mean square error of delay estimation and the bit error rate of coherent demodulation can reach 10^-9 s and 10^-3, respectively. The field measurement results show that the distances from the test point to the three transmitting stations are 53km, 77km, and 96km, respectively, and the positioning root mean square error is 48.523m. The research results can be used to achieve long-distance high-precision ranging and communication functions. The signal envelope is constant and can be parasitically carried in public frequency modulation and amplitude modulation signals, realizing covert transmission without affecting the host signal.