High dynamic high precision intermediate frequency simulation satellite signal generating method

Abstract

The invention relates to a method for generating medium-frequency satellite signals with high dynamic situation and high precision, and the method comprises the following steps: 1) parameters of a radio-frequency carrier are received, including the initial pseudo distance, the speed, the acceleration and the jerk; 2) the carrier phase with high precision and including Doppler frequency shift is generated by a method of three-phase carrier phase accumulation; 3) a medium-frequency carrier signal is obtained after carrier phase truncation by searching sine and cosine tables; 4) parameters of a ranging code are received, including the initial pseudo distance, the speed, the acceleration and the jerk; 5) a code clock with high precision is generated by a method of three-phase code phase accumulation; 6) under the action of the code clock, I-path and Q-path spreading codes are generated; 7) I-path and Q-path navigation messages are read and binary addition is carried out with the spreading codes; 8) the spreading codes are molded, filtered and modulated onto the medium carrier; 9) power control and digital-to-analog conversion are carried out to the spreading signals, thus obtaining the medium-frequency analogue satellite signals. The method has the advantages of simple structure, smooth speed without step and high precision.

Description

technical field [0001] The invention relates to a satellite signal generation method, more specifically, to a high dynamic and high precision intermediate frequency signal generation method for satellite signal simulation. Background technique [0002] The high-dynamic satellite signal simulator can accurately simulate the satellite signal received by the carrier. As a high-precision test equipment, it has powerful functions and is widely used in the fields of civil and national defense scientific experiments. Its typical uses include simulating high dynamic signals transmitted by satellites to test the acquisition performance of receivers, as an accuracy comparison standard to test the dynamic measurement accuracy of receivers, and to design specific signal verification measurement schemes, etc. In recent years, China has gradually established its own navigation and positioning system. While continuously developing and improving various performance indicators of the system,...

AI Technical Summary

Problems solved by technology

Its main disadvantages are: 4 times zero interpolation is used to generate higher frequency signals, followed by a bandpass filter to filter out each image frequency component. This method has a low working clock and complex structure, which reduces the analog accuracy of the signal.

Using a first-order direct digital synthesis (DDS) model, the signal with acceleration and jerk is simulated by updating the velocity parameters within a time interval. This method leads to a step-by-step velocity, and the simulation accuracy can only be increased by shortening the parameter update time interval.

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