Method and system for estimating carrier frequency deviation

Abstract

The invention provides a system for estimating a carrier frequency deviation, comprising the following modules: a correlator module, a peak value search engine, an averaging device module, a phase angle difference calculator module and a carrier frequency deviation calculator module, wherein the correlator module is used for carrying out correlation calculation on a baseband signal and a locally-generated PN (Pseudo-Noise) sequence; the peak value search engine is used for carrying out peak value searching after receiving a parallel correlated value output by the correlator module, further determining a starting position of a PN section in the input baseband signal and feeding the position information back to the correlator module; the averaging device module is used for averaging results of the multiple times of correlated calculation of front and back sections, which are output by a correlator; the phase angle difference calculator module is used for calculating a phase angle difference of the correlated calculation and outputting the result; and the carrier frequency deviation calculator module is used for calculating an estimation value of the carrier frequency deviation and taking the estimation value of the carrier frequency deviation as an estimation value of PN rough estimation. The system has the beneficial effects that the problem that PN rough capturing is inaccurate when stronger multi-path interference exists can be effectively solved, and the robustness of the system under an actual wireless transmission channel can be improved.

Description

technical field [0001] The present invention relates to digital signal transmission, in particular to the initial acquisition process of carrier in terrestrial digital television broadcasting transmission system, which can reliably and quickly acquire carrier by using the spreading gain of pseudo-random sequence (PN sequence) in frame structure. Background technique [0002] In the wireless digital communication system, the carrier recovery module in the receiver is the most basic module. Especially in the terrestrial digital TV transmission system, due to the instability of the carrier frequency of the output intermediate frequency or baseband signal of the tuner (tuner), and the possible Doppler frequency offset, the received radio frequency signal will be There is a serious carrier frequency deviation. The existence of carrier frequency deviation will cause the phase of the received signal to be ambiguous, and the correct transmitted signal cannot be demodulated, and it ...

AI Technical Summary

Problems solved by technology

[0020] The purpose of the present invention is to solve the problem of inaccurate PN rough capture when there is strong multipath interference, and to improve the robustness of the system under actual wireless transmission channels

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