CN113253214B - A Phase Correction Method Between Channels - Google Patents

Abstract

The invention relates to the technical field of phase correction, in particular to a phase correction method among channels. The invention recovers the frequency component phase deviation of the cross-channel broadband signal in different channels by correcting the phase among the channels of the analog filter bank, thereby achieving the purpose of recovering all information of the broadband signal without distortion as much as possible. Compared with the method of taking the content of one channel by judging the channel criterion and abandoning other channels, the method effectively reserves all information of the signal and fully prepares for the subsequent processing work such as signal characteristic extraction and the like.

Description

A Phase Correction Method Between Channels

technical field

The invention relates to the technical field of phase correction, in particular to a phase correction method between channels.

Background technique

The receiving range of electronic reconnaissance is usually expressed as a non-cooperative receiving method. Therefore, it is impossible to match the receiving method of reconnaissance receiving. To achieve full probability receiving within the monitoring bandwidth, the channelized receiver can be used to monitor the target bandwidth. . However, with the development of radar technology, radar signals are becoming more and more concealed, and their instantaneous bandwidth is wider and wider, that is, the signal either appears in the channel, or spans two adjacent channels, and even the received wideband signal may be The problem arises across several channels.

According to the existing algorithm, when the signal appears in the transition zone, one of the channels can be selected as the channel where the current signal is located by using the channel synthesis judgment method for processing. However, this method brings irreversible loss to the complete signal pattern. If you want to retain the signal completely, you need to retain the information of several channels spanned by the signal, but each radio frequency filter used as channel division has no effect on the radio frequency signal The phase responses of the channels are different, so to restore the signal without distortion, it is necessary to correct the phase between the channels.

Therefore, there is an urgent need for improvement in the existing signal processing methods. The radio frequency signals spanning several channels should be optimized and improved to improve the complete effectiveness of signal processing and reduce signal distortion. Therefore, it is necessary to propose a more reasonable technical solution. Solve the deficiencies in the existing technology.

SUMMARY OF THE INVENTION

In order to solve the defects of the prior art mentioned in the above content, the present invention provides a phase correction method between channels. By performing phase correction processing on radio frequency signals spanning multiple channels, signal distortion is reduced and the processing of radio frequency signals is improved. Effect.

In order to achieve the above object, the technical scheme specifically adopted in the present invention is:

An inter-channel phase correction method, comprising:

The radio frequency complex signal at the junction of two adjacent channels M and M+1 is injected into the two channels respectively;

Collect the RF signal data of channel M and channel M+1, and perform Fourier transform at the uninterrupted point of the flow respectively;

Obtain the Fourier transform result of any frame corresponding to channel M and channel M+1, obtain the peak value from the transform result, and obtain the phase corresponding to the peak value, thereby obtaining the phase difference between the two peaks;

Calculate the group delay difference between channel M and channel M+1 according to the phase difference between channel M and channel M+1;

Specify the initial channel, and convert the group delay difference existing in the remaining channels into the group delay difference relative to the initial channel;

Based on the initial channel, the weight value of the Fourier transform result of each channel is correspondingly set in combination with the group delay difference, and the corresponding product of the weight value and the corresponding Fourier transform result is obtained to obtain the spectral information of all signals.

The phase correction method disclosed above can process signals with a wider bandwidth by performing Fourier transform and weight calculation on signals of multiple channels, and using the finally obtained value as spectrum information. The signal is completely preserved and the distortion of the signal is avoided.

Further, in the content disclosed in the present invention, the collection of the radio frequency signal data of channel M and channel M+1, respectively, performs Fourier transform of the uninterrupted point of the flowing water, which can be realized in various ways. Optimize and name one of the possible options, including:

Perform Fourier transform of length N _M on the radio frequency signal data of channel M, and perform Fourier transform of length N _M +1 on the radio frequency signal data of channel M+1 at the same time, wherein the Fourier transform length is N _M and N _M+1 satisfy the following relationship:

Wherein, f _sM and f _sM+1 are the sampling rates of channel M and channel M+1, respectively.

Further, in the content disclosed in the present invention, the Fourier transform result of any frame on channel M and channel M+1 is obtained, the peak value is obtained from the transform result, and the phase corresponding to the peak value is obtained, thereby obtaining The phase difference between the two peaks can be realized in a variety of feasible ways. Here, we will optimize and list one of the feasible options, including:

计算峰值所对应的相位，并根据

计算峰值相对所对应的相位差；according to

Calculate the phase corresponding to the peak, and according to

Calculate the phase difference corresponding to the peak relative;

为信道M傅里叶变换结果中峰值频谱数据对应的相位，

为信道M+1傅里叶变换结果中峰值频谱数据对应的相位，

为相位差。Among them, I and Q are the real and imaginary parts of the spectral data corresponding to the peaks in the Fourier transform result,

is the phase corresponding to the peak spectral data in the Fourier transform result of channel M,

is the phase corresponding to the peak spectral data in the channel M+1 Fourier transform result,

is the phase difference.

Still further, in the content disclosed in the present invention, the group delay difference between channel M and channel M+1 is calculated according to the phase difference between channel M and channel M+1; a variety of feasible methods can be used to calculate The group delay difference is not uniquely limited. Here, an optimization is performed and one of the feasible options is listed. Specifically, the group delay difference is calculated as follows:

为相邻两个信道之间的相位差，f为注入该相邻两信道的射频复信号的频率，Δτ为相邻两个信道之间存在的群延迟差。in,

is the phase difference between two adjacent channels, f is the frequency of the radio frequency complex signal injected into the two adjacent channels, and Δτ is the group delay difference existing between the two adjacent channels.

Further, in the process of calculating the group delay difference, in addition to calculating the group delay difference between two adjacent channels, the initial channel should also be specified, and the group delay difference existing in the remaining channels should be converted into the group delay relative to the initial channel. Poor; optimize here and cite one of the possible options, including:

If channel 1 is set as the initial channel among multiple channels, the group delay differences of the remaining channels relative to the initial channel are:

Δτ ₁₂ =Δτ ₁₂

Δτ ₁₃ =Δτ ₁₂ +Δτ ₂₃

Δτ ₁₄ =Δτ ₁₂ +Δτ ₂₃ +Δτ ₃₄

...

Δτ _1K =Δτ ₁₂ +Δτ ₂₃ +…+Δτ _K-1K

where K is the total number of channels.

Further, in the content disclosed in the present invention, the weight value of the Fourier transform result of each channel is correspondingly set based on the initial channel and the group delay difference, and a variety of feasible schemes can be adopted, which are carried out here. Optimize and name one of the possible options, including:

Set the weight value of the Fourier transform result of the m ₁ (m ₁ =1,2,3...N ₁ ) point in channel 1 to 1, and the m _K (m _K =1,2,3... The corresponding weight value of N _K ) point is

f_sK是信道K的采样率，Δτ_1K为信道K与信道1之间的群延迟差，N_K为第K个信道里傅里叶变换的长度。in,

f _sK is the sampling rate of channel K, Δτ _1K is the group delay difference between channel _K and channel 1, and NK is the length of the Fourier transform in the Kth channel.

Still further, in the above disclosure, the initial passband frequency of the channel 1 radio frequency filter is f ₁ , then n ₁ =[f ₁ -mod(f ₁ ,f _s1 )]/f _s1 , where mod (f ₁ , f _s1 ) represents the remainder of f ₁ to f _s1 , and f _s1 is the sampling rate of channel 1. According to this method, the value rule of n ₁ on channel 1 is calculated; similarly, the value rule of n ₂ , n ₃ , n ₄ . . . n _k of other channels at the passband frequency can be obtained in turn.

Compared with the prior art, the present invention has the following beneficial effects:

Since the phase responses of each bandpass filter in the analog filter bank in the channelized receiver are different to the signal, when the spectrum of the wideband signal spans multiple channels, all the spectral components of the signal will be scattered in several channels, and The phase corresponding to the spectral components will deviate from the true phase of the signal. The invention restores the phase deviation of the frequency components of the cross-channel wideband signal in different channels by correcting the phase between the channels of the analog filter bank, so as to achieve the purpose of restoring all the information of the wideband signal without distortion as much as possible. Compared with the method of choosing one channel content by judging the channel criterion and giving up other channels, this method effectively retains all the information of the signal, and is fully prepared for the subsequent processing work such as signal feature extraction.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be It is regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic diagram of the division of channels by a filter bank.

FIG. 2 is a schematic diagram of a flow of phase correction between channels.

FIG. 3 is a schematic diagram of three-channel division in an embodiment.

Detailed ways

The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

It should be noted here that the descriptions of these embodiments are used to help the understanding of the present invention, but do not constitute a limitation of the present invention. Specific structural and functional details disclosed herein are merely illustrative of example embodiments of the present invention. The present invention, however, may be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

Example

Aiming at the situation that a signal is distorted by using a method of selecting a channel when processing a radio frequency signal across multiple channels, this embodiment discloses a phase correction method to solve the problem existing in the prior art.

Specifically, the method adopted in this embodiment is:

As shown in Figure 1 and Figure 2, an inter-channel phase correction method includes:

S01: inject the radio frequency complex signals at the junction of two adjacent channels M and M+1 into the two channels respectively;

S02: Collect the RF signal data of channel M and channel M+1, and perform Fourier transform at the uninterrupted point of the flow respectively;

S03: Obtain the Fourier transform result of any frame corresponding to channel M and channel M+1, obtain peak values from the transform results, and obtain the phase corresponding to the peak value, thereby obtaining the phase difference between the two peaks;

S04: Calculate the group delay difference between channel M and channel M+1 according to the phase difference between channel M and channel M+1;

S05: Specify the initial channel, and convert the group delay difference existing in the remaining channels into the group delay difference relative to the initial channel;

S06: Based on the initial channel, the weight value of the Fourier transform result of each channel is correspondingly set in combination with the group delay difference, and the corresponding product of the weight value and the corresponding Fourier transform result is obtained to obtain the spectrum information of all signals .

The phase correction method disclosed above can process signals with a wider bandwidth by performing Fourier transform and weight calculation on signals of multiple channels, and using the finally obtained value as spectrum information. The signal is completely preserved and the distortion of the signal is avoided.

In the content disclosed in this embodiment, the collection of the radio frequency signal data of the channel M and the channel M+1 is respectively performed as the Fourier transform of the uninterrupted point of the flowing water, which can be realized in a variety of ways, and the optimization is carried out here. Identify one of the possible options, including:

Perform Fourier transform of length N _M on the radio frequency signal data of channel M, and perform Fourier transform of length N _M +1 on the radio frequency signal data of channel M+1 at the same time, wherein the Fourier transform length is N _M and N _M+1 satisfy the following relationship:

Wherein, f _sM and f _sM+1 are the sampling rates of channel M and channel M+1, respectively.

In the content disclosed in this embodiment, the Fourier transform result of any frame on channel M and channel M+1 is obtained, the peak value is obtained from the transform result, and the phase corresponding to the peak value is obtained, so as to obtain the two The phase difference of the peak at the peak can be realized in a variety of feasible ways. Here, we will optimize and list one of the feasible options, including:

计算峰值所对应的相位，并根据

计算峰值相对所对应的相位差；according to

Calculate the phase corresponding to the peak, and according to

Calculate the phase difference corresponding to the peak relative;

为信道M傅里叶变换结果中峰值频谱数据对应的相位，

为信道M+1傅里叶变换结果中峰值频谱数据对应的相位，

为相位差。Among them, I and Q are the real and imaginary parts of the spectral data corresponding to the peaks in the Fourier transform result,

is the phase corresponding to the peak spectral data in the Fourier transform result of channel M,

is the phase corresponding to the peak spectral data in the channel M+1 Fourier transform result,

is the phase difference.

In the content disclosed in this embodiment, the group delay difference between the channel M and the channel M+1 is calculated according to the phase difference between the channel M and the channel M+1; the group delay can be calculated in various feasible ways. The difference is not uniquely limited. Here is an optimization and one of the feasible options is listed. Specifically, the group delay difference is calculated as follows:

为相邻两个信道之间的相位差，f为注入该相邻两信道的射频复信号的频率，Δτ为相邻两个信道之间存在的群延迟差。in,

is the phase difference between two adjacent channels, f is the frequency of the radio frequency complex signal injected into the two adjacent channels, and Δτ is the group delay difference existing between the two adjacent channels.

In the process of calculating the group delay difference, in addition to calculating the group delay difference between two adjacent channels, the initial channel should also be specified, and the group delay difference existing in the remaining channels should be converted into the group delay difference relative to the initial channel; this optimization and cite one of the possible options, including:

If channel 1 is set as the initial channel among multiple channels, the group delay differences of the remaining channels relative to the initial channel are:

Δτ ₁₂ =Δτ ₁₂

Δτ ₁₃ =Δτ ₁₂ +Δτ ₂₃

Δτ ₁₄ =Δτ ₁₂ +Δτ ₂₃ +Δτ ₃₄

...

Δτ _1K =Δτ ₁₂ +Δτ ₂₃ +…+Δτ _K-1K

where K is the total number of channels.

In the content disclosed in this embodiment, the initial channel is used as the reference, and the weight value of the Fourier transform result of each channel is correspondingly set in combination with the group delay difference. Various feasible schemes can be adopted, and optimization is carried out here. Identify one of the possible options, including:

Set the weight value of the Fourier transform result of the m ₁ (m ₁ =1,2,3...N ₁ ) point in channel 1 to 1, and the m _K (m _K =1,2,3... The corresponding weight value of N _K ) point is

f_sK是信道K的采样率，Δτ_1K为信道K与信道1之间的群延迟差，N_K为第K个信道里傅里叶变换的长度。in,

f _sK is the sampling rate of channel K, Δτ _1K is the group delay difference between channel _K and channel 1, and NK is the length of the Fourier transform in the Kth channel.

In the above disclosure, the initial passband frequency of the channel 1 radio frequency filter is f ₁ , then n ₁ =[f ₁ -mod(f ₁ ,f _s1 )]/f _s1 , where mod(f ₁ ,f _s1 ) represents the remainder of f ₁ to f _s1 , and f _s1 is the sampling rate of channel 1. According to this method, the value rule of n ₁ on channel 1 is calculated; similarly, the value rule of n ₂ , n ₃ , n ₄ . . . n _k of other channels at the passband frequency can be obtained in turn.

When the method disclosed in this embodiment is specifically applied to perform phase calibration, corresponding parameter values may be set according to actual conditions. A specific implementation situation is presented here, as shown in FIG. 3 , including three channels.

Specifically, the sampling rate of channel 1 is f _s1 =600 MHz, the sampling rate of channel 2 is f _s2 =560 MHz, and the sampling rate of channel 3 is f _s3 =600 MHz. The number of Fourier transform points for each channel is N ₁ =120, N ₂ =112, and N ₃ =120.

When performing the phase correction according to the method disclosed in this embodiment, the following steps are included:

S01: A complex signal with a frequency of 1450MHz injected at the junction of channel 1 and channel 2

S02: Select any time to start, and perform continuous 120 and 112-point Fourier transform on the data collected by channel 1 and channel 2, respectively.

进而得到相位差

S03: Take any frame in step S02, and search for peaks in the Fourier transform result, assuming that the peak IQs of channel 1 are I ₁ and Q ₁ respectively; the peak IQs of channel 2 are I ₂ and Q ₂ , respectively. Obtained from the phase formula

to get the phase difference

S04: Using the group delay difference formula, the group delay difference can be obtained

S05: A complex signal with a frequency of 1600 MHz is injected at the junction of channel 2 and channel 3.

S06: According to the start time selected in step S02, perform continuous 112 and 120-point Fourier transform on the data collected by channel 2 and channel 3, respectively.

进而得到相位差

S07: Take any frame in step S06, and search for the peak value in the Fourier transform result. It is assumed that the peak IQs of channel 2 are I' ₂ and Q' ₂ respectively; the peak IQs of channel 3 are I ₃ and Q ₃ respectively. Obtained from the phase formula

to get the phase difference

S08: Using the group delay difference formula, the group delay difference can be obtained

S09: Taking channel 1 as the initial channel union, the group delay difference between channel 2 and channel 1 is Δτ ₁₂ , and the group delay difference between channel 3 and channel 1 is Δτ ₁₃ =Δτ ₁₂ +Δτ ₂₃ .

信道2通带为1450MHz～1600MHz，采样率为560MHz，所以

同理n₃＝2。信道1的权值均为1；由公式可得：S10: Weight calculation: first calculate n ₁ , n ₂ , n ₃ . The passband of channel 1 is 1200MHz to 1450MHz, and the sampling rate is 600MHz.

The passband of channel 2 is 1450MHz to 1600MHz, and the sampling rate is 560MHz, so

Similarly n ₃ =2. The weight of channel 1 is all 1; it can be obtained from the formula:

The weight of channel 2 is:

其中m₂＝1,2,3…112；

where m ₂ =1,2,3...112;

The weight of channel 3 is:

其中m₃＝1,2,3…120。

where m ₃ =1,2,3...120.

S11: Multiply the weights of the three channels in step S09 and the pipeline Fourier transform results of the three channels in step S02 correspondingly in sequence. The result obtained is the spectrum information of all signals in the frequency band of 1200MHz to 1750MHz.

The above are the implementations enumerated in this embodiment, but this embodiment is not limited to the above-mentioned optional implementations. Those skilled in the art can arbitrarily combine the above-mentioned ways to obtain other various implementations. Other various forms of implementation can be derived under the inspiration. The above-mentioned specific embodiments should not be construed as limiting the protection scope of this embodiment, and the protection scope of this embodiment should be defined in the claims, and the description can be used to interpret the claims.

Claims (6)

1. A method for correcting phase between channels, comprising:

respectively injecting radio frequency complex signals at the junction of two adjacent channels M, M +1 into the two channels;

collecting radio frequency signal data of a channel M and a channel M +1, and respectively carrying out Fourier transform on continuous running points;

acquiring Fourier transform results of any corresponding frame on the channel M and the channel M +1, respectively acquiring peak values from the transform results, and acquiring phases corresponding to the peak values, thereby acquiring the phase difference of the two peak values;

calculating to obtain a group delay difference between the channel M and the channel M +1 according to the phase difference between the channel M and the channel M + 1;

designating an initial channel, and converting group delay differences existing in other channels into group delay differences relative to the initial channel;

and taking the initial channel as a reference, correspondingly setting a weight value of the Fourier transform result of each channel by combining the group delay difference, and correspondingly multiplying the weight value and the corresponding Fourier transform result to obtain the frequency spectrum information of all the signals.

2. The method according to claim 1, wherein the fourier transform of the continuous stream points is performed on the radio frequency signal data of the acquisition channel M and the acquisition channel M +1, respectively, and the method comprises:

making length of radio frequency signal data of channel M to be N_MAnd the length of the data of the radio frequency signal of the channel M +1 is N at the same time_M+1Wherein the Fourier transform has a length N_MAnd N_M+1The following relationship is satisfied:

wherein f is_sM、f_sM+1Are respectively a channel MAnd the sampling rate of channel M + 1.

3. The method according to claim 1, wherein the fourier transform results of any frame on the channel M and the channel M +1 are obtained, and the peak values are obtained from the transform results respectively, and the phase corresponding to the peak value is obtained, thereby obtaining the phase difference between the two peak values; the method comprises the following steps:

according to

Calculating the phase corresponding to the peak value and according to

Calculating the phase difference corresponding to the peak value;

wherein I and Q are the real part and imaginary part of the spectrum data corresponding to the peak value in the Fourier transform result,

for the phase corresponding to the peak spectral data in the fourier transform result of channel M,

for the phase corresponding to the peak spectral data in the fourier transform result of channel M +1,

is the phase difference.

4. The method according to claim 1, wherein the group delay difference between the M channel and the M +1 channel is calculated according to the phase difference between the M channel and the M +1 channel; the group delay difference is calculated specifically as follows:

wherein,

f is the frequency of the radio frequency complex signal injected into the two adjacent channels, and Δ τ is the group delay difference existing between the two adjacent channels.

5. The method according to claim 1, wherein the initial channel is designated, and the group delay difference existing in the remaining channels is converted into a group delay difference with respect to the initial channel; the method comprises the following steps:

setting channel 1 as an initial channel among the plurality of channels, and then the group delay differences of the remaining channels with respect to the initial channel are respectively:

Δτ₁₂＝Δτ₁₂

Δτ₁₃＝Δτ₁₂+Δτ₂₃

Δτ₁₄＝Δτ₁₂+Δτ₂₃+Δτ₃₄

……

Δτ_1K＝Δτ₁₂+Δτ₂₃+…+Δτ_K-1K

where K is the total number of channels.

6. The method of claim 1, wherein the initial channel is used as a reference, and the weight value of the fourier transform result of each channel is correspondingly set in combination with the group delay difference; the method comprises the following steps:

m-th in channel 1₁(m₁＝1,2,3…N₁) The weighted value of the point Fourier transform result is set to 1, the mth of the channel K_K(m_K＝1,2,3…N_K) The point corresponding weight value is

Wherein，

f_sKIs the sampling rate of the channel K, Δ τ_1KIs the group delay difference, N, between channel K and channel 1_KThe length of the Fourier transform of the Kth channel; the passband of the channel 1 RF filter has a starting frequency f₁Then n is₁＝[f₁-mod(f₁,f_s1)]/f_s1Where mod (f)₁,f_s1) Denotes f₁To f is paired_s1Remainder, f_s1Is the sampling rate of channel 1, and, similarly, n_k＝[f_k-mod(f_k,f_sk)]/f_skWhere mod (f)_k,f_sk) Denotes f_kTo f is paired_skRemainder, f_skIs the sampling rate of channel k.

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