Polarity diversity reception device and method based on SOQPSK-TG signal

Abstract

The invention discloses a polarity diversity reception method based on an SOQPSK-TG signal. The method comprises the following steps: adopting two ADCs to transfer a received levogyration polarity signal and a received dextrorotation polarity signal into digital signals respectively; adopting an automatic gain control loop to enable the two digital signals to be constant in amplitude or in a threshold value section; tracking frequency difference and phase difference of the two gained digital signals through a difference module loop to fulfill same frequency and phase locking of the two digital signals; adopting maximal-ratio combining to obtain average SNR gain; tracking Doppler frequency shift to conduct carrier recovery; conducting position timing clock recovery; tracking clock phase shift and frequency shift between a receiver and a transmitter. The invention further discloses an SOQPSK-TG signal modulation and polarity diversity reception device based on FPGA. The modulation and reception device utilizes the characteristics of constant envelope and high spectral efficiency of the SOQPSK-TG to meet modern satellite communication demand; the polarity diversity reception technology is introduced to avoid deep zero point influence; system performance is improved.

Description

technical field [0001] The invention relates to the technical field of satellite communication, in particular to an FPGA-based SOQPSK-TG signal polarization diversity receiving device and method thereof. Background technique [0002] The channel of the satellite communication system has the characteristics of limited power and bandwidth and non-linearity, so it is necessary to use a modulation method with high bandwidth efficiency as much as possible while ensuring sufficient power (see "Beidas B F, Cioni S, De Bie U, et al. Continuous phase modulation for broadband satellite communications: design and trade-offs [J]. International Journal of Satellite Communications and Networking, 2013, 31(5): 249-262" and "Maral G, Bousquet M. Satellite communications systems: systems, techniques and technology [M]. 5th edition. California: John Wiley & Sons, 2011"). [0003] Traditional BPSK (Binary Phase Shift Keying, binary phase shift keying), QPSK (Quadrature Phase Shift Keying, qua...

AI Technical Summary

Problems solved by technology

For example, dual-loop phase-locked and triple-loop phase-locked polarization diversity reception technology based on FM modulation (see "Jiang Dong. A new type of dual-loop phase-locked polarization diversity receiver [J]. Telemetry and Remote Control, 1995, 16(5): 52- 65" and "Xue Sanbao. A Practical Polarization Diversity Receiving Scheme[J]. Telecommunications Technology, 1996,36(4):1-4"), due to the use of an analog phase-locked loop, the stability and reliability Poor; BPSK-based digital double-loop phase-locked polarization diversity reception (see "Chen Zhu. Research on Digital Diversity Receiver [D]. Chongqing University, 2006"), its spectrum characteristics are not good, and it can no longer meet the requirements of modern satellite communications. need

The traditional reception system for SOQPSK modulation also has relatively mature technical achievements (see "Hosseini E, Perrins E.FPGA implementation of a coherent SOQPSK-TG demodulator[C] / / MILCOM2011-2011IEEE Military Communications Conference.Piscataway: IEEE, 2011: 471-476" and "Kumaraswamy B, Perrins E. Simplified 2-State Detectors for SOQPSK[C] / / IEEE Military Communications Conference. New York: IEEE, 2007:1272-1278"), but when the signal has deep fading performance will deteriorate dramatically

[0007] Therefore, it is necessary to provide a new signal diversity receiving method in satellite communication to overcome the signal fading problem in satellite communication

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