Quadrature Error Correction Method for Zero-IF Receiver

A zero-IF receiver and quadrature error technology, applied in the direction of error prevention, correct operation test, digital transmission system, etc., can solve the problems of constant quadrature unbalance and dependence on specific communication modes, etc., and achieve wide dynamic range, The test results are credible and the received signal quality is good

CN109560825BActive Publication Date: 2020-10-2010TH RES INST OF CETC
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2020-10-20

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Abstract

The invention discloses a zero intermediate frequency receiver quadrature error correction method, which can significantly improve the dynamic range and image frequency rejection ratio of a zero intermediate frequency receiver. The method is implemented according to the following technical scheme: a quadrature error detection module selects a baseband frequency and sends the baseband frequency toa correction waveform generation device so as to generate a test signal covering the whole receiving bandwidth, the quadrature error detection module collects the test signal of positive and negativefrequencies from the correction waveform generation device, extracts broadband parameter estimated values of a local oscillation error and a baseband error and introduces the values into a quadratureerror correction module through an error analysis module; and the quadrature error correction module analyzes frequency domain, amplitude and phase data and comprehensively generates a baseband errorcorrection filter and a direct weighting coefficient to correct the gain and phase relative error of a Q-channel in the whole frequency band range.
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Description

technical field

[0001] The invention relates to a correction of quadrature error associated with a digital communication system, in particular to a broadband quadrature error correction method applied to a zero-IF receiver. Background technique

[0002] In recent years, software radio, as a new technology, has had a revolutionary impact on the traditional radio technology field. Zero-IF has become very practical. Although zero-IF technology has been developed for many years, and some types of paging and GSM mobile phones have also been adopted, the current zero-IF technology cannot meet the high performance requirements of the circuit. The traditional mode of modulation and demodulation is that the radio signal RF enters the antenna, converts it into an intermediate frequency IF and then converts it into a baseband (I, Q signal). The zero-IF is a method in which the signal is directly changed from RF to baseband without intermediate frequency modulation and demodulation. ...

Examples

Embodiment Construction

[0016] refer to figure 1 . According to the present invention, the quadrature error in the quadrature error model can be divided into two types: local oscillator error and baseband error. The quadrature error model does not represent the absolute error of the signal, but represents the relative error between the I channel and the Q channel. When implemented, the I channel is used as the reference channel, and all mismatches are considered to be caused by the Q channel. Therefore, correcting quadrature error only involves correcting the relative gain and phase errors of the Q channel over the entire frequency band.

[0017] In the zero-IF receiver, a correction waveform generating device, a switching switch, a quadrature error detection module, an error analysis module, a quadrature error correction module, and a quadrature error model are set. The quadrature error model first converts the quadrature The error is divided into two types of local oscillator error and baseband e...