Carrier capturing method in large dynamic range

Abstract

The invention discloses a carrier capturing method in a large dynamic range. The method is used for capturing uplink carrier signals on a spacecraft. The method comprises the following steps of: carrying out down conversion on received uplink carrier signals by using local carrier at a fixed frequency interval; filtering to obtain intermediate-frequency signals after down conversion; extracting the intermediate-frequency signals by using three sampling frequencies to obtain a high-speed extraction signal, an intermediate-speed extraction signal and a low-speed extraction signal; judging the peak values of the high-speed extraction signal, the intermediate-speed extraction signal and the low-speed extraction signal respectively, capturing the uplink carrier signals, and carrying out capture confirmation on the captured uplink carrier signals to obtain confirmed uplink carrier signals; and acquiring and outputting the carrier frequency and carrier power of the confirmed uplink carrier signals. By the method, single carrier can be captured at extremely low signal-to-noise ratio, and large frequency change range and high frequency change rate are adapted.

Description

technical field [0001] The invention relates to a large dynamic range carrier acquisition method. Background technique [0002] The carrier acquisition method in the prior art has a signal threshold processing capability signal-to-noise ratio C / N0 of the transponder on the already-flying lunar star CE-1 / 2 is 47dBHz, while in deep space exploration, the signal-to-noise ratio of the received signal is dynamic The range is huge, C / N0 from 17dBHz to 117dBHz. At the same time, in order to meet the needs of deep space exploration, the carrier acquisition method meets the requirements of large Doppler range and high Doppler conversion rate of deep space detection signals. In previous deep space exploration missions, on-board processing equipment waited for ground signals at the frequency agreed with the ground station. In deep space exploration, on-board equipment was required to actively search for signals in the Doppler range to save time. [0003] The carrier acquisition algor...

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Problems solved by technology

The carrier acquisition methods in the above literatures only deal with the large dynamic range, and do not propose how to deal with the high frequency sweep frequency rate and the equipment actively looking for signals to save the acquisition time, so it is difficult to meet the needs of deep space measurement and control communication

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