Signal correction method and correction device

Abstract

A signal correction method applied to correct mismatch between an in-phase signal path and an orthographic signal path of a transmitter comprises the following steps: additionally setting at least one mixer correction coefficient at a transmitting end of the transmitter; looping back at least one mixer test signal from the transmitting end to conduct spectrum analysis to obtain at least one mixer spectrum analysis result; adjusting the at least one mixer correction coefficient of the transmitting end according to the at least one mixer spectrum analysis result; and additionally using an in-phase signal path finite impulse response filter and an orthogonal signal path finite impulse response filter to correct mismatch between a low-pass filter of the in-phase signal path at the transmitting end and a low-pass filter of the orthographic signal path at the transmitting end. A similar mismatch correction operation can also be applied to a receiver.

Description

technical field [0001] The embodiments disclosed in the present invention relate to a calibration method and related circuits of a communication system, especially a calibration method applied to a transmitter where an in-phase (I) signal path does not match a quadrature (Q) signal path and related devices. Background technique [0002] Generally speaking, the more complex modulation technology can usually contain more information data, that is, the transmission rate can be increased by complex modulation processing, such as 64-Quadrature Amplitude Modulation (64-QAM) , or even 256-QAM. Therefore, the demand for high-order quadrature amplitude modulation is becoming more and more popular. If high-order quadrature amplitude modulation is expected to have a good transmission and reception effect, the error vector magnitude (ErrorVector Magnitude, EVM) of the communication system must be increased correspondingly, and one of the most important factors affecting the error vect...

AI Technical Summary

Problems solved by technology

The second is that due to the unavoidable imperfection in the circuit manufacturing process, the two groups of components on the in-phase path and the quadrature path will not completely match each other, such as the low-pass filter on the in-phase path and the quadrature path ( Low-pass filter, LPF), analog-to-digital converter (analog-to-digital converter, ADC), digital-to-analog converter (digital-to-analog converter, DAC) or gain amplifier (gain amplifier) ​​and other components do not match, As a result, there will be a difference between the signals passing through the in-phase path and the quadrature path. When the signal passes through the in-phase path and the quadrature path that do not match each other, an image interference signal (such as figure 1 shown), resulting in reduced signal quality

Images