阅读说明：本技术 基于施密特正交化来消除iq两路信号相位误差的方法 (The method of IQ two paths of signals phase error is eliminated based on Schimidt orthogonalization ) 是由 郭连平 孟婕 蒋俊 曾浩 田雨 王猛 叶芃 王厚军 于 2019-08-01 设计创作，主要内容包括：本发明公开了一种基于施密特正交化来消除IQ两路信号相位误差的方法,在不考虑噪声影响下,通过对I、Q通道中混频处理后的信号进行ADC采样,然后,以I通道信号为基准,对Q通道信号进行施密特正交化处理,再将I通道信号和处理后的Q通道信号构成复数信号并进行FFT处理,最后绘制频谱图,观察频谱图是否有镜像谱分量,如果有镜像谱分量,则更新Q通道信号,继续进行施密特正交化,直到绘制的频谱图没有镜像谱分量,从而完成相位误差的校正。(The invention discloses a kind of methods that IQ two paths of signals phase error is eliminated based on Schimidt orthogonalization, in the case where not considering influence of noise, by to I, signal in the channel Q after Frequency mixing processing carries out ADC sampling, then, on the basis of I channel signal, Schimidt orthogonalization processing is carried out to Q channel signal, I channel signal and treated Q channel signal are constituted into complex signal again and carry out FFT processing, finally draw spectrogram, whether observation spectrogram has mirror image spectral component, if there is mirror image spectral component, then update Q channel signal, continue Schimidt orthogonalization, until the spectrogram of drafting does not have mirror image spectral component, to complete the correction of phase error.)

1. a kind of method for eliminating IQ two paths of signals phase error based on Schimidt orthogonalization, which is characterized in that including following Step:

(1), by the two paths of signals cos (ω of the radio frequency analog signal r (t) of input and local oscillator output_cT) andRespectively Pass through the frequency mixer Frequency mixing processing in the channel I, Q, whereinFor unbalance phase, ω_cFor carrier frequency；

(2), the radio-frequency component of the signal after Frequency mixing processing is filtered out by low-pass filter in the channel I, Q；

(3), filtered signal is sampled by ADC in the channel I, Q, obtains signal xi [n]=cos (ω in the channel I, Q nT_s)、Wherein, ω is base-band signal frequency, and n is the discrete instants of time；

(4), with I channel signal x_i[n] is benchmark benchmark, to Q channel signal x_q[n] carries out Schimidt orthogonalization processing；

x'_q[n]=x_q[n]-(<x_i[n],x_q[n]>/<x_i[n],x_i[n]>)·x_i[n]

Wherein,<>indicates to seek inner product operation；

(5), I channel signal and treated Q channel signal are constituted into complex signal, and carries out FFT processing, then draw frequency spectrum Figure, whether observation spectrogram has mirror image spectral component, if there is mirror image spectral component, then by Q channel signal x_q[n] is updated to x'_q[n], Return again to step (4)；If not having mirror image spectral component, phase error correction terminates.

Technical field

The invention belongs to error correction techniques fields, more specifically, are related to one kind and are disappeared based on Schimidt orthogonalization Except the method for IQ two paths of signals phase error.

Background technique

In wireless communication field, by higher sensitivity and outstanding dynamic range, super heterodyne architectures, which become, to be received The most widely used structure of machine.But due to needing the bandpass filter of high q-factor for mirror image inhibition and channel selection, superhet Formula receiver the disadvantages of there is also structure is complicated, volume power consumption is bigger than normal and not easy of integration, this seriously constrains superheterodyne Machine is to the application in the sensitive products such as power consumption, volume.Compared with superheterodyne receiver, zero intermediate frequency formula receiver is in down coversion When by radiofrequency signal Direct Conversion to base band, do not need mirror image and inhibit and channel selection filter, have and be easy to single-chip integration, knot The advantages that structure is simple and cost is low in energy consumption, obtains extensive concern in recent years.

But zero intermediate frequency reciver uses quadrature down-conversion architecture, strict demand must generate that frequency is identical, phase phase difference 90 ° of two-way orthogonal local oscillation signal, frequency mixer in two path channels, filter, amplifier also must complete one to the response of signal It causes.However, the physical limit and circuit design error of device will lead to the phase on the road I and the road Q signal in actual hardware circuit It is inconsistent with amplitude, i.e. IQ imbalance problem.It includes image disturbing signal, serious shadow that IQ imbalance problem, which will lead to baseband signal, The signal-to-noise ratio and dynamic range of acoustic system.Therefore, it is necessary to the influences for eliminating IQ imbalance to system that takes appropriate measures.And its In the critical issue to be solved be exactly i/q signal orthogonal problem.

The major measure for eliminating IQ imbalance problem at present has optimization circuits and digital domain compensation calibration.Circuit optimization The method of design is mainly to pass through the consistency for improving device, and the reduction road I is inconsistent with the road Q phase and amplitude, but can not Completely eliminate IQ imbalance.Numeric field compensation calibration is compensated in base band to signal using the algorithm of Digital Signal Processing, Image interference caused by inhibiting IQ uneven is current largely quilt due to its good calibration result and succinct operating process The method used.

Summary of the invention

It is an object of the invention to overcome the deficiencies of the prior art and provide one kind, and IQ two is eliminated based on Schimidt orthogonalization The method of road signal phase error carries out Schimidt orthogonalization processing to Q channel signal, to have on the basis of I channel signal Effect solves the problems, such as the signal phase difference in the channel I, Q not equal to 90 degree.

For achieving the above object, the present invention is a kind of eliminates IQ two paths of signals phase error based on Schimidt orthogonalization Method, which comprises the following steps:

(1), by the two paths of signals cos (ω of the radio frequency analog signal r (t) of input and local oscillator output_cT) and Pass through the frequency mixer Frequency mixing processing in the channel I, Q respectively, whereinFor unbalance phase, ω_cFor carrier frequency；

(2), the radio-frequency component of the signal after Frequency mixing processing is filtered out by low-pass filter in the channel I, Q；

(3), filtered signal is sampled by ADC in the channel I, Q, obtains signal x in the channel I, Q_i[n]= cos(ωnT_s)、Wherein, ω is base-band signal frequency, and n is the discrete instants of time, T_sIt is adopted for ADC Sample rate；

(4), with I channel signal x_iOn the basis of [n], to Q channel signal x_q[n] carries out Schimidt orthogonalization processing；

x′_q[n]=x_q[n]-(<x_i[n],x_q[n]>/<x_i[n],x_i[n]>)·x_i[n]

Wherein,<>indicates to seek inner product operation；

(5), I channel signal and treated Q channel signal are constituted into complex signal, and carries out FFT processing, then draw frequency Spectrogram, whether observation spectrogram has mirror image spectral component, if there is mirror image spectral component, then by Q channel signal x_q[n] is updated to x '_q [n] returns again to step (4)；If not having mirror image spectral component, phase error correction terminates.

Goal of the invention of the invention is achieved in that

The present invention is based on Schimidt orthogonalizations come the method for eliminating IQ two paths of signals phase error, is not considering influence of noise Under, by carrying out ADC sampling to the signal after Frequency mixing processing in the channel I, Q, then, on the basis of I channel signal, to the channel Q Signal carries out Schimidt orthogonalization processing, then I channel signal and treated Q channel signal are constituted complex signal and carried out Spectrogram is finally drawn in FFT processing, and whether observation spectrogram has mirror image spectral component, if there is mirror image spectral component, then it is logical to update Q Road signal, continues Schimidt orthogonalization, until the spectrogram of drafting does not have mirror image spectral component, to complete phase error Correction.

Meanwhile also having the present invention is based on Schimidt orthogonalization come the method for eliminating IQ two paths of signals phase error and following have Beneficial effect:

(1), in the prior art, Schimidt orthogonalization processing is accomplished that the processing between linearly independent vector group, and The signal errors that the present invention takes the lead in for Schimidt orthogonalization processing being used for interchannel corrects；

(2), the present invention, which can overcome, cannot be completely eliminated IQ imbalance problem in optimization circuits method, moreover it is possible to overcome Image interference problem caused by can not inhibiting IQ uneven in numeric field compensation calibration method；

(3), calibration result of the present invention it is good and and operation it is succinct, the signal phase difference in the effectively solution channel I, Q is not equal to 90 degree of the problem of.

Detailed description of the invention

Fig. 1 is the method flow diagram for eliminating IQ two paths of signals phase error the present invention is based on Schimidt orthogonalization；

Fig. 2 is that the error in the channel I/Q in quadrature demodulation introduces schematic diagram；

Fig. 3 is the Schimidt orthogonalization schematic diagram of i/q signal；

Fig. 4 is FFT spectrum figure before and after Schimidt orthogonalization.

Specific embodiment

A specific embodiment of the invention is described with reference to the accompanying drawing, preferably so as to those skilled in the art Understand the present invention.Requiring particular attention is that in the following description, when known function and the detailed description of design perhaps When can desalinate main contents of the invention, these descriptions will be ignored herein.