Quadrature Error Correction Method for Zero-IF Receiver

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.

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. ...

AI Technical Summary

Problems solved by technology

The existing digital domain correction methods have problems such as dependence on specific communication modes and constant quadrature unbalance within the signal bandwidth.

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