Doppler frequency cancellation based full digital main carrier tracking method

Abstract

The all-digital main carrier tracking method based on Doppler frequency cancellation belongs to the field of measurement and control communication. From the complex signal after the Doppler frequency difference, the FIR low-pass filter is used to extract the main carrier signal carrying the negative Doppler residual frequency difference information, and the positive and negative cancellation of the Doppler residual frequency difference is completed, so as to achieve the main carrier signal The purpose of carrier tracking. This method overcomes problems such as loop structure and parameter design trouble caused by the traditional method of using a phase-locked loop, Doppler residual error cannot be completely eliminated, etc., and is suitable for tracking the main carrier in the USB measurement and control system.

Description

technical field [0001] The invention relates to an all-digital main carrier tracking method based on Doppler frequency cancellation, which is suitable for main carrier tracking of unified S-band (Unified S-band, USB) measurement and control signals. This method does not need a feedback control loop, and can better achieve the purpose of eliminating Doppler frequency offset. This scheme is especially suitable for the tracking control of the main carrier under the condition of Doppler frequency change rate. The method belongs to the field of measurement and control communication. Background technique [0002] During the communication process, due to the radial movement speed (the speed along the straight line direction of the communication object) between the communication objects, the Doppler effect appears between the received signal and the transmitted signal, so that there is a Doppler frequency difference; In addition, in most cases, the movement of the communication ob...

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Problems solved by technology

Using a phase-locked loop to track the remaining Doppler frequency difference has a simple structure and does not occupy much resources, but there is always a certain frequency residual, and the Doppler frequency difference cannot be completely eliminated; when the Doppler change rate is large , in order to track the change of the upper Doppler frequency, a high-order phase-locked loop is required, and the design of a high-order phase-locked loop involves the stability of the loop, which is very difficult to implement

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