WO2015127767A1

WO2015127767A1 - Method and device for generating discrete domain phase noise

Info

Publication number: WO2015127767A1
Application number: PCT/CN2014/084585
Authority: WO
Inventors: 侯晓辉
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-02-27
Filing date: 2014-08-18
Publication date: 2015-09-03
Also published as: CN104883155B; CN104883155A

Abstract

A method and device for generating a discrete domain phase noise. The method comprises: converting an analog filter generating a phase noise in an analog domain into a digital filter and determining a parameter of the digital filter; cascading a predetermined number of the digital filters into a digital filter system and utilizing a Gaussian white noise to drive the digital filter system; acquiring an output signal of the digital filter system on the basis of the parameter of the digital filter; and, acquiring a phase noise of a discrete time-domain on the basis of the output signal.

Description

Method and device for generating discrete domain phase noise

The present invention relates to the field of wireless communication systems, and in particular, to a method and apparatus for generating discrete domain phase noise. BACKGROUND OF THE INVENTION In wireless communications, the carrier signal is often not a single frequency sine wave due to the instability of the local oscillator of the transmitter and receiver. This instability is often measured by phase noise. For this reason, when the carrier frequency of the system is relatively high, when the wireless communication system uses a high-order modulation mode, the influence of phase noise is usually not negligible. Therefore, it is often necessary to construct the phase noise in the modeling of the communication system. In the mold, the phase noise is generally expressed by its power density spectrum. Therefore, most of the literatures present the method of phase noise in the analog domain. Few documents have given phase noise modeling in discrete digital domains. method.

However, in the study of digital baseband systems, the signals are represented in discrete digital domains. Therefore, the addition of phase noise in the simulation of digital baseband systems must take into account the generation of phase noise in discrete domains. However, there is no method in the prior art that can generate discrete phase phase noise. SUMMARY OF THE INVENTION A technical problem to be solved by embodiments of the present invention is to provide a method and apparatus for generating discrete-domain phase noise capable of generating discrete-domain phase noise.

To solve the above technical problem, an embodiment of the present invention provides a method for generating discrete-domain phase noise, including the following steps:

Converting an analog filter that produces phase noise in the analog domain to a digital filter, and determining parameters of the digital filter;

A predetermined number of the digital filters are cascaded to form a digital filter system, and the digital filter system is driven by Gaussian white noise;

Obtaining an output signal of the digital filter system according to parameters of the digital filter; Phase noise in the discrete time domain is obtained from the output signal.

Preferably, the step of determining parameters of the digital filter comprises:

Obtaining a preset phase noise power spectral density model;

Obtaining a zero point frequency and a pole frequency of the phase noise according to the preset phase noise power spectral density module;

Calculating parameters of the digital filter according to a zero point frequency and a pole frequency of the phase noise; and the step of obtaining phase noise of the discrete time domain according to the output signal includes:

Phase noise in the discrete time domain required by the predetermined phase noise power spectral density model is derived from the output signal.

Preferably, the parameters of the digital filter include coefficients of the digital filter and a gain factor of the digital filter, and the step of calculating the parameters of the digital filter according to the zero point frequency and the pole frequency of the phase noise includes:

Calculating a gain factor of the digital filter according to a zero point frequency of the phase noise, a pole frequency, and a preset phase noise power spectral density model; acquiring a frequency response of the digital filter and a time domain transfer function of the digital filter; A coefficient of the digital filter is obtained according to a frequency response of the digital filter, a time domain transfer function of the digital filter, a gain factor of the digital filter, and a zero point frequency and a pole frequency of the phase noise.

Preferably, the step of acquiring the frequency response of the digital filter and the time domain transmission function of the digital filter comprises:

Obtaining a Z domain transfer function of the digital filter;

A frequency response of the digital filter is obtained according to a Z domain transfer function of the digital filter; a Z domain transfer function of the digital filter is converted to a time domain transfer function of the digital filter. Preferably, the number is obtained according to a frequency response of the digital filter, a time domain transfer function of the digital filter, a gain factor of the digital filter, and a zero point frequency and a pole frequency of the phase noise. The steps of the coefficients of the filter include:

Processing the frequency response of the digital filter to obtain a frequency response approximation of the digital filter Value expression

Comparing a time domain transfer function of the digital filter with a frequency response approximation expression of the digital filter to obtain a coefficient expression of the digital filter;

Substituting the zero point frequency of the phase noise, the pole frequency, and the gain factor of the digital filter into the coefficient expression of the digital filter results in a coefficient value of the digital filter. Preferably, the step of obtaining the zero point frequency and the pole frequency of the phase noise according to the preset phase noise power spectral density model comprises: obtaining a first pole frequency from a curve corresponding to the preset phase noise spectral density model Obtaining a pole density factor of the digital filter, and calculating respective pole frequencies of the phase noise according to the first pole frequency and the pole density factor;

Obtaining a falling factor of the digital filter, and calculating a zero point frequency of the phase noise according to the pole density factor, the falling factor, and the calculated pole frequency. Also in order to solve the above problem, the embodiment of the present invention further provides another method for generating phase noise of a discrete domain, comprising: discretizing the phase noise power spectral density of the analog domain to obtain a discretized power spectral density;

Frequency shifting the discretized power spectral density;

Frequency domain white noise is generated, and the frequency domain white noise is conjugate symmetrized; phase noise in the discrete frequency domain is obtained according to the processed discretized power spectral density and the processed frequency domain white noise. Preferably, the step of obtaining the phase noise in the discrete frequency domain according to the processed discretized power spectral density and the processed frequency domain white noise comprises:

Multiplying the processed discretized power spectral density by the processed frequency domain white noise; performing multiplication and realization processing on the multiplicative result and performing inverse Fourier transform to obtain phase noise in a discrete frequency domain . Preferably, the step of discretizing the phase noise power spectral density of the analog domain to obtain the discretized power speech density comprises: Determine the sampling frequency;

Determining the number of discrete points of phase noise that need to be generated;

Converting a phase noise power spectral density of the analog domain into a discretized power spectral density according to the sampling frequency and the discrete number of points;

The step of generating frequency domain white noise includes:

Frequency domain white noise is generated based on the frequency of use.

Preferably, the sampling frequency is greater than or equal to 2 times the cutoff frequency of the phase noise to be generated; the quotient of the sampling frequency divided by the discrete points is smaller than the starting frequency of the phase noise to be generated.

Also in order to solve the above technical problem, an embodiment of the present invention further provides a discrete domain phase noise generating apparatus, including: a digital filter design unit, a system construction unit, and a phase noise generating unit;

The digital filter design unit is configured to convert an analog filter that generates phase noise in an analog domain into a digital filter, and determine parameters of the digital filter;

The system building unit is configured to cascade a preset number of the digital filters to form a digital filter system, and drive the digital filter system with Gaussian white noise;

The phase noise generating unit is configured to obtain an output signal of the digital filter system according to a parameter of the digital filter; and obtain phase noise of a discrete time domain according to the output signal.

Preferably, the digital filter design unit is configured to:

Obtaining a preset phase noise power spectral density model;

Calculating parameters of the digital filter according to a zero point frequency and a pole frequency of the phase noise; the phase noise generating unit is configured to obtain, according to the output signal, a discrete time domain required by the preset phase noise power spectral density model Phase noise.

Preferably, the parameters of the digital filter include coefficients of the digital filter and a gain factor of the digital filter; the digital filter design unit is configured to:

According to the zero frequency of the phase noise, the pole frequency, and the preset phase noise power spectral density The model calculates a gain factor of the digital filter;

Acquiring a frequency response of the digital filter and a time domain transfer function of the digital filter; a frequency response according to the digital filter, a time domain transfer function of the digital filter, a gain factor of the digital filter, and a The zero point frequency and the pole frequency of the phase noise are obtained as coefficients of the digital filter.

Preferably, the digital filter design unit is configured to:

Obtaining a Z domain transfer function of the digital filter;

A frequency response of the digital filter is obtained according to a Z domain transfer function of the digital filter; a Z domain transfer function of the digital filter is converted to a time domain transfer function of the digital filter. Preferably, the digital filter design unit is configured to:

Processing the frequency response of the digital filter to obtain a frequency response approximation expression of the digital filter;

Substituting the zero point frequency of the phase noise, the pole frequency, and the gain factor of the digital filter into the coefficient expression of the digital filter results in a coefficient value of the digital filter.

Preferably, the digital filter design unit is configured to:

Obtaining a first pole frequency from a curve corresponding to the preset phase noise spectral density model; acquiring a pole density factor of the digital filter, and calculating phase noise according to the first pole frequency and the pole density factor Each pole frequency;

Obtaining a falling factor of the digital filter, and calculating a zero point frequency of the phase noise according to the pole density factor, the falling factor, and the calculated pole frequency.

Also in order to solve the above technical problem, the embodiment of the present invention further provides another discrete domain phase noise generating apparatus, including: a discretization processing unit, a frequency shift processing unit, a frequency domain white noise generating unit, and a frequency domain white noise processing unit. And a phase noise generating unit;

The discretization processing unit is configured to discretize the phase noise power spectral density of the analog domain to obtain a discretized power spectral density; The frequency shift processing unit is configured to perform frequency shift processing on the discretized power spectral density; the frequency domain white noise generating unit is configured to generate frequency domain white noise;

The frequency domain white noise processing unit is configured to perform conjugate symmetry processing on the frequency domain white noise;

The phase noise generating unit is arranged to obtain phase noise in a discrete frequency domain based on the processed discretized power spectral density and the processed frequency domain white noise.

Preferably, the phase noise generating unit is configured to:

Multiplying the processed discretized power spectral density by the processed frequency domain white noise; performing multiplication and realization processing on the multiplicative result and performing inverse Fourier transform to obtain phase noise in a discrete frequency domain .

Preferably, the discretization processing unit is configured to:

Determine the sampling frequency;

The phase noise power spectral density of the analog domain is converted to a discretized power spectral density based on the sample frequency and the discrete number of points.

The embodiment of the invention provides a method and a device for generating phase noise in a discrete domain, which can perform phase noise modeling on the basis of real-time data collection of simulated phase noise, thereby obtaining phase noise of the discrete domain and accelerating phase noise. The development progress of the suppression and elimination algorithm is achieved for the purpose of quickly launching the product. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic flow chart of a method for generating discrete-domain phase noise according to Embodiment 1 of the present invention;

2 is a schematic flowchart of calculating parameters of a filter according to a pole-zero frequency according to Embodiment 1 of the present invention; 3 is a block diagram of a system for generating phase noise in a time domain according to Embodiment 1 of the present invention; FIG. 4 is a schematic flowchart of a method for generating phase noise in a discrete domain according to Embodiment 2 of the present invention;

FIG. 5 is a schematic block diagram of a phase noise generating phase noise according to Embodiment 2 of the present invention; FIG. 6 is a schematic structural diagram of a discrete domain phase noise generating apparatus according to Embodiment 3 of the present invention;

FIG. 7 is a schematic structural diagram of a device for generating discrete-domain phase noise according to Embodiment 4 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

Embodiment 1:

As shown in FIG. 1, the embodiment provides a method for generating discrete-domain phase noise, including the following steps:

Step 101: Convert an analog filter that generates phase noise in the analog domain into a digital filter, and determine parameters of the digital filter.

This step is a process of designing a digital filter, which is to design a digital filter by an analog filter, and convert the analog filter into a digital filter, mainly by digitizing the analog filter, that is, mapping the analog filter from the S domain to In the Z domain, a digital filter is obtained, and then the parameters of the digital filter are determined. The parameters of the digital filter in this embodiment include: the coefficients of the digital filter and the gain factor of the digital filter.

Step 102: Cascading a preset number of the digital filters to form a digital filter system, and driving the digital filter system with Gaussian white noise.

In this embodiment, the digital filters involved above are connected in series, and then white noise (having a power spectral density of 1) is used as a driving signal to finally obtain phase noise in a discrete time domain. The number of digital filters of this embodiment can be determined according to actual needs. Step 103: Obtain an output signal of the digital filter system according to parameters of the digital filter.

The white noise driving is utilized in the method of this embodiment. Since the power spectral density is always 1 , the phase noise obtained after being transmitted through the cascaded digital filter is only related to the coefficient of the digital filter. In this embodiment, the phase noise of the discrete time domain can be obtained by obtaining the coefficients of the digital filter.

Step 104: Obtain phase noise of discrete time domain according to the output signal.

In this embodiment, the digital filter is designed by using an analog domain filter, and then the digital filter designed by cascading, using white noise as an input signal, and finally obtaining phase noise of discrete time domain by cascading digital filter; The method mainly uses the white noise power spectral density to always be 1, and then filters the white noise by designing a suitable digital filter, and finally extracts the phase noise of the discrete time domain to be parameterized from the output signal of the digital filter, and the phase noise is only It is related to the coefficient of the digital filter, so the phase noise in the discrete time domain can be easily obtained. The phase noise can be obtained by modeling the phase noise without performing real-time simulation of the simulated phase noise. Accelerate the development of phase noise suppression and cancellation algorithms to achieve rapid product launch.

Since the model of the discrete-domain phase noise is determined in the field of wireless communication systems, that is, the power spectral density model of the phase noise is determined, the method of the present embodiment can obtain the phase noise to be obtained by analyzing the power spectral density of a given phase noise. The zero frequency and the pole frequency are then used to calculate the parameters of the digital filter using the zero and pole frequencies. Therefore, the process of calculating the parameters of the digital filter in the above step 101 includes:

Obtaining a preset phase noise power spectral density model;

Calculating the parameters of the digital filter according to the zero point frequency and the pole frequency of the phase noise; the process of obtaining the phase noise of the discrete time domain according to the output signal in the above step 104 includes: obtaining the preset according to the output signal The phase noise of the discrete time domain required by the phase noise power spectral density model. According to the method introduced in the above embodiment, the present embodiment can quickly generate phase noise in a discrete time domain that meets the requirements of a specific phase noise power language model.

In this embodiment, the parameters of the digital filter may include a coefficient of the digital filter and a gain factor of the digital filter, wherein the step of calculating the parameter of the digital filter according to the zero point frequency and the pole frequency of the phase noise includes, as shown in picture 2:

Step 201: Calculate a gain factor of the digital filter according to a zero point frequency of the phase noise, a pole frequency, and a preset phase noise power spectral density model.

Step 202: Acquire a frequency response of the digital filter and a time domain transfer function of the digital filter.

The acquisition process can include:

Obtaining a Z domain transfer function of the digital filter;

A frequency response of the digital filter is obtained according to a Z domain transfer function of the digital filter; a Z domain transfer function of the digital filter is converted to a time domain transfer function of the digital filter. Step 203: Obtaining the digital filter according to a frequency response of the digital filter, a time domain transfer function of the digital filter, a gain factor of the digital filter, and a zero point frequency and a pole frequency of the phase noise. coefficient.

The process of calculating the coefficients of the digital filter includes:

Processing the frequency response of the digital filter to obtain an approximate expression of the frequency response of the digital filter; for example, performing Taylor expansion, etc.

Preferably, the step of obtaining the zero point frequency and the pole frequency of the phase noise according to the preset phase noise power spectral density model in the method of the embodiment includes:

Obtaining a first pole frequency from a curve corresponding to the preset phase noise spectral density model; acquiring a pole density factor of the digital filter, according to the first pole frequency and the The pole density factor calculates the respective pole frequencies of the phase noise;

The following describes the process of digital filter design:

In the analog domain, phase noise can be generated in the following form.

In the present form, ^S _Z1 is the first zero point, and ^S pi is the pth pole

The frequency response characteristic of H _a (s) satisfies the following conditions

p(f) is the power spectral density of the phase noise to be generated.

Therefore, to achieve analog domain to digital domain conversion, the filter needs to be converted from the analog domain to the digital domain, using the classical conversion formula, where τ is the sample time interval. In the following discussion, the normalized power spectral density of the noise is always assumed to be one.

1 -I s T

Ss„→ lz e ^x

Can obtain the z domain transfer function of the discrete filter

(2)

In fact, given the power spectrum of the phase noise, the zero point frequency and the pole frequency of the phase noise can be known, denoted here as s _zi = -2 f _zi , s _pi = -2 f _{pi , respectively} . Let ^T= , z=exp (j2nfT) , f _s be the sampling frequency, s _zl =-2 f _zl , s _pi =^f _pi s

Substituting equation (2), the frequency response of the discrete filter is H(f )

In addition, by converting equation (2) from the Z domain to the time domain, the transmission function of the digital filter in the filtering system can be obtained.

Comparison

Coefficient.

The calculation process of the pole-zero frequency is described below:

Given the given phase noise power spectral density model, the frequency of the first pole can be easily determined from the zero pole frequency method.

Where -2 ≤ ≤ 2 is the descent factor per 10 octaves; the pole density factor of the filter is the number of poles per 10 octaves, and the range of h is usually 0.5 ≤ ≤ 1.5.

The filter gain factor calculation process is described below: It should be noted that for a given phase noise power language model P (f), when the digital filter is driven by discrete noise, the following formula can be used.

To determine the value of the filter gain factor A.

Through the above derivation calculation process, the parameters of the digital filter, namely the coefficient and the gain factor, can be calculated, and then the designed digital filter is cascaded, and the designed digital filter is driven by Gaussian white noise to obtain the design requirements. Phase noise in discrete time domains.

The process of generating phase noise in discrete time domain in this embodiment is illustrated by a specific example:

Model of power spectral density.

Step 1: For this form of noise, in order to simplify the problem, you can choose a pair of poles. Obviously, the pole can be taken as f _pl =f _p . When using a pair of poles, the pole density factor can be ignored. Impact, this will bring problems to the problem. Of course, if the accuracy of the consideration is high, it is necessary to use the pole density factor, as in the formulas (5) and (6). Here, for the sake of simplicity of consideration, and the accuracy of the general situation, the influence of the pole density factor is not considered. Zero point f _z i=f _z .

The value of the zero pole can be obtained according to the process described above.

The second step: Determine the time interval τ of the sample. According to the Nyquist sample theorem, the time interval τ needs to satisfy ≥2f _zl . The third step: From the above equation (4) and H (f) is obtained IIR filter coefficients ^{^{ai = eXP (_27lfplT), ^}} -εχ (-2πί ζ1 Τ) ο a fourth step: (7) determining the above equation discrete The gain factor A of the IIR filter, due to the approximation in the actual simulation, needs to be fine-tuned according to the simulation result. According to the linear characteristic, the result of this fine-tuning is easily determined according to the simulated power spectrum and the power word actually generated.

Step 5: After the parameters of the digital filter are calculated, the phase noise θ (η) is obtained by a white noise excitation filter having a discrete power spectral density of 1. As shown in Figure ₃ , the digital filtering of the design After cascading, the white noise is used to drive, and finally the phase noise of the time domain can be obtained according to the parameters of the digital filter.

Embodiment 2:

As shown in FIG. 4, this embodiment provides a method for generating phase noise in a discrete domain, including the following steps:

Step 401: Discretize the phase noise power spectral density of the analog domain to obtain a discretized power spectral density.

The discretization process can include:

Determine the sampling frequency;

Preferably, the sampling frequency in the embodiment is greater than or equal to 2 times the intercept frequency of the phase noise to be generated; the quotient of the sampling frequency divided by the discrete points is smaller than the starting frequency of the phase noise to be generated.

Step 402: Perform frequency shift processing on the discretized power spectral density.

Step 403: Generate frequency domain white noise, and perform conjugate symmetry processing on the frequency domain white noise. The process of generating white noise in the frequency domain may include:

Frequency domain white noise is generated based on the sampling frequency.

Step 404: Obtain phase noise in a discrete frequency domain according to the processed discretized power spectral density and the processed frequency domain white noise.

The process of obtaining phase noise can include the following processes:

Multiplying the processed discretized power spectral density by the processed frequency domain white noise; performing multiplication and realization processing on the multiplicative result and performing inverse Fourier transform to obtain phase noise in a discrete frequency domain . In this embodiment, the foregoing steps 401, 402, and 403 do not have a strict timing relationship, and may be performed first in step 403 and then in steps 401 and 402, or may be performed in step 401 and then in step 403, and finally in step 402.

The generation process of the frequency domain phase noise in this embodiment will be described below. Referring to FIG. 5:

Step 1: Determine the sampling frequency F _s and the number of discrete points of phase noise to be generated ^. For example, according to the sample theorem, the sampling frequency should satisfy F _s ≥ 2f _max , where f _max is the cutoff frequency of the phase noise spectrum to be generated.

Determine the number of discrete points of phase noise that need to be generated, denoted here as N _s , for good frequency division

F

Resolution, requirement ⁼ ^<^. Step 2: Discretize the continuous phase noise power spectral density to obtain a discrete phase noise power spectral density ^p d ( ^k ). Wave amplitude frequency response

, and then through the amplitude frequency

It should be possible to get P _d (k). Step 3: To make P _d ( ^k ) suitable for fft change, perform frequency shift transformation on ^p d ( ^k ), frequency shift transformation

Step 4: Generate frequency domain white noise W (k) , where Var ( 1 = 1 , sequence length is +1

Step 5: Perform conjugate symmetry on the white noise W (k) in the frequency domain to obtain W'

W» is defined as: N

W (k), 0 ≤ k ≤

W (k)

N

W*(kN _s ), 1≤ k≤ N -1

Step 6: Let PN(k)=W'(k)P _d (k)

Step 7: Perform averaging and realization on PN (k) to obtain phase noise in the frequency domain

In order to make the phase noise mean 0 and the output phase noise to be real,

, PN(0)=0

PN : abs(PN(k))

2

Then the ifft (inverse Fourier transform) of the processed PN(k) is used to obtain the phase noise of the discrete domain.

Pn(n)-ifft(PN(k)) The method of this embodiment performs a series of calculation processes on the phase noise generated in the analog domain to finally obtain phase noise in a discrete frequency domain, which is a given phase noise power spectrum. The phase noise required by the density model. For example, it can be assumed that phase noise of the following form is generated,

The step process can generate the frequency domain phase noise required by the P(f) model, where / _∞χ = / _ζ ,

J f max = J fz ° Embodiment 3: As shown in FIG. 6, the embodiment provides a discrete-domain phase noise generating apparatus, including: a digital filter design unit, a system construction unit, and a phase noise generating unit. The digital filter design unit is configured to convert an analog filter that generates phase noise in the analog domain into a digital filter, and determine parameters of the digital filter;

The system building unit is configured to cascade a preset number of the digital filters to form a digital filter system, and drive the digital filter system with Gaussian white noise; The phase noise generating unit is configured to obtain an output signal of the digital filter system according to a parameter of the digital filter; and obtain phase noise of a discrete time domain according to the output signal.

Preferably, the digital filter design unit is configured to:

Obtaining a preset phase noise power spectral density model;

Preferably, the digital filter design unit is configured to:

Obtaining a Z domain transfer function of the digital filter;

Substituting the zero frequency of the phase noise, the pole frequency, and the gain factor of the digital filter The coefficient expression of the digital filter results in a coefficient value of the digital filter.

Preferably, the digital filter design unit is configured to:

For the processing of each unit in this embodiment, reference may be made to the corresponding steps in the method described in the first embodiment.

Embodiment 4:

As shown in FIG. 7, the embodiment provides a discrete domain phase noise generating apparatus, including: a discretization processing unit, a frequency shift processing unit, a frequency domain white noise generating unit, a frequency domain white noise processing unit, and phase noise generating. Unit

The discretization processing unit is configured to discretize the phase noise power spectral density of the analog domain to obtain a discretized power spectral density;

The frequency shift processing unit is configured to perform frequency shift processing on the discretized power spectral density; the frequency domain white noise generating unit is configured to generate frequency domain white noise;

The frequency domain white noise processing unit is configured to perform conjugate symmetry processing on the frequency domain white noise; the phase noise generating unit is configured to obtain a discrete frequency domain according to the processed discretized power spectral density and the processed frequency domain white noise Phase noise.

Preferably, the phase noise generating unit is configured to:

Preferably, the discretization processing unit is configured to: Determine the sampling frequency;

The frequency domain white noise generating unit is configured to generate frequency domain white noise according to the frequency of use. In this embodiment, preferably, the sampling frequency is greater than or equal to 2 times the cutoff frequency of the phase noise to be generated; the quotient of the sampling frequency divided by the discrete points is less than the phase noise to be generated. Starting frequency.

For the processing of each unit in this embodiment, reference may be made to the corresponding steps in the method described in Embodiment 2 above.

The discrete-domain phase noise generating apparatus of this embodiment can change the phase noise of the analog domain to obtain phase noise in a discrete frequency domain.

Those skilled in the art should understand that the components of the apparatus and/or system provided by the embodiments of the present invention described above, as well as the steps of the method, can be implemented by a general computing device, which can be concentrated in a single calculation. On the device, or distributed over a network of computing devices, optionally, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device, or They are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated into a single integrated circuit module. Thus, the invention is not limited to any particular combination of hardware and software.

The above is a further detailed description of the present invention in connection with the specific embodiments, and it is not intended that the specific embodiments of the invention are limited to the description. It will be apparent to those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the invention.

Industrial applicability The embodiment of the invention can perform phase noise modeling without performing real-time simulation of phase noise, and can obtain phase noise of the discrete domain, accelerate the development progress of the phase noise suppression and cancellation algorithm, and achieve the purpose of rapidly launching the product. .

Claims

claims

1. A method for generating discrete domain phase noise, including:

Convert an analog filter that generates phase noise in the analog domain into a digital filter, and determine the parameters of the digital filter;

A preset number of digital filters are cascaded to form a digital filter system, and Gaussian white noise is used to drive the digital filter system; the output signal of the digital filter system is obtained according to the parameters of the digital filter; The phase noise in the discrete time domain is obtained according to the output signal.

2. The method for generating discrete domain phase noise according to claim 1, wherein the step of determining parameters of the digital filter includes:

Obtain the preset phase noise power spectral density model;

Obtain the zero frequency and pole frequency of the phase noise according to the preset phase noise power spectral density model;

The parameters of the digital filter are calculated according to the zero frequency and pole frequency of the phase noise; the step of obtaining the phase noise in the discrete time domain according to the output signal includes:

The phase noise in the discrete time domain required by the preset phase noise power spectral density model is obtained according to the output signal.

3. The method for generating discrete domain phase noise according to claim 2, wherein the parameters of the digital filter include coefficients of the digital filter and gain factors of the digital filter, and the zero frequency and pole of the phase noise are The steps for calculating the frequency parameters of the digital filter include:

Calculate the gain factor of the digital filter according to the zero frequency, pole frequency and preset phase noise power spectral density model of the phase noise; Obtain the frequency response of the digital filter and the time domain transfer function of the digital filter; The coefficients of the digital filter are obtained according to the frequency response of the digital filter, the time domain transfer function of the digital filter, the gain factor of the digital filter, and the zero frequency and pole frequency of the phase noise.

4. The method for generating discrete domain phase noise according to claim 3, wherein the obtained data The steps of obtaining the frequency response of the word filter and the time domain transfer function of the digital filter include: obtaining the Z domain transfer function of the digital filter;

Obtain the frequency response of the digital filter according to the Z-domain transfer function of the digital filter; convert the Z-domain transfer function of the digital filter into a time-domain transfer function of the digital filter.

5. The method for generating discrete domain phase noise according to claim 3, wherein: the frequency response of the digital filter, the time domain transfer function of the digital filter, and the gain factor of the digital filter As well as the zero frequency and pole frequency of the phase noise, the steps of obtaining the coefficients of the digital filter include:

Process the frequency response of the digital filter to obtain an approximate expression of the frequency response of the digital filter;

Compare the time domain transfer function of the digital filter with the frequency response approximation expression of the digital filter to obtain the coefficient expression of the digital filter;

Substitute the zero frequency, pole frequency of the phase noise and the gain factor of the digital filter into the coefficient expression of the digital filter to obtain the coefficient value of the digital filter.

6. The method for generating discrete domain phase noise according to any one of claims 2 to 5, wherein the step of obtaining the zero frequency and pole frequency of the phase noise according to the preset phase noise power spectral density model includes:

Obtain the first pole frequency from the curve corresponding to the preset phase noise spectral density model; obtain the pole density factor of the digital filter, and calculate the phase noise based on the first pole frequency and the pole density factor Each pole frequency of;

Obtain the drop factor of the digital filter, and calculate the zero frequency of the phase noise according to the pole density factor, the drop factor and the calculated pole frequency.

7. A method for generating discrete domain phase noise, including:

Discretize the phase noise power spectral density in the analog domain to obtain the discretized power density;

Perform frequency shift processing on the discretized power spectral density;

Generate frequency domain white noise, and perform conjugate symmetry processing on the frequency domain white noise; The phase noise in the discrete frequency domain is obtained based on the processed discretized power spectral density and the processed frequency domain white noise.

8. The method for generating discrete domain phase noise according to claim 7, wherein the step of obtaining phase noise in the discrete frequency domain based on the processed discretized power spectral density and the processed frequency domain white noise includes:

Multiply the processed discretized power spectral density and the processed frequency domain white noise; average and real-number the multiplied results and perform inverse Fourier transform to obtain discrete frequency domain phase noise. .

9. The method for generating discrete domain phase noise according to claim 7 or 8, wherein the step of discretizing the phase noise power spectral density in the analog domain to obtain the discretized power spectral density includes:

Determine sampling frequency;

Determine the number of discrete points of phase noise that needs to be generated;

Convert the phase noise power spectral density of the analog domain into a discretized power spectral density according to the sampling frequency and the number of discrete points;

The steps of generating frequency domain white noise include:

Frequency domain white noise is generated according to the adopted frequency.

10. The method for generating discrete domain phase noise according to claim 9, wherein the sampling frequency is greater than or equal to 2 times the cutoff frequency of the phase noise to be generated; the quotient of the sampling frequency divided by the number of discrete points The value is less than the starting frequency of the phase noise to be generated.

11. A device for generating discrete domain phase noise, including: a digital filter design unit, a system construction unit and a phase noise generation unit;

The digital filter design unit is configured to: convert an analog filter that generates phase noise in the analog domain into a digital filter, and determine parameters of the digital filter;

The system construction unit is configured to: cascade a preset number of the digital filters to form a digital filter system, and use Gaussian white noise to drive the digital filter system;

The phase noise generating unit is configured to: obtain the data according to the parameters of the digital filter. The output signal of the word filter system; phase noise in the discrete time domain is obtained according to the output signal.

12. The device for generating discrete domain phase noise as claimed in claim 11, wherein the digital filter design unit is configured to:

Obtain the preset phase noise power spectral density model;

Obtain the zero frequency and pole frequency of the phase noise according to the preset phase noise power spectral density module;

The parameters of the digital filter are calculated according to the zero frequency and pole frequency of the phase noise; the phase noise generation unit is configured to obtain the discrete time domain required by the preset phase noise power spectral density model according to the output signal phase noise.

13. The device for generating discrete domain phase noise according to claim 12, wherein the parameters of the digital filter include coefficients of the digital filter and gain factors of the digital filter;

The digital filter design unit is set to:

14. The device for generating discrete domain phase noise as claimed in claim 13, wherein the digital filter design unit is configured to:

Obtain the Z-domain transfer function of the digital filter;

15. The device for generating discrete domain phase noise as claimed in claim 13, wherein the digital filter design unit is configured to:

Process the frequency response of the digital filter to obtain an approximate frequency response expression of the digital filter; Comparing the time domain transfer function of the digital filter with the approximate frequency response expression of the digital filter to obtain the coefficient expression of the digital filter;

16. The device for generating discrete domain phase noise according to any one of claims 12 to 15, wherein the digital filter design unit is set to:

17. A device for generating discrete domain phase noise, including: a discretization processing unit, a frequency shift processing unit, a frequency domain white noise generation unit, a frequency domain white noise processing unit and a phase noise generation unit; the discretization processing unit is configured In order to discretize the phase noise power spectral density in the analog domain to obtain the discretized power spectral density;

The phase noise generating unit is configured to obtain discrete frequency domain phase noise based on the processed discretized power spectral density and the processed frequency domain white noise.

18. The discrete domain phase noise generating device as claimed in claim 17, wherein the phase noise generating unit is configured to:

19. The device according to claim 17 or 18, wherein the discretization processing unit is a device Set to:

Determine sampling frequency;

Convert the phase noise power spectral density in the analog domain into a discretized power spectral density according to the sampling frequency and the number of discrete points.

20. The device for generating discrete domain phase noise according to claim 19, wherein the sampling frequency is greater than or equal to 2 times the cutoff frequency of the phase noise to be generated; the quotient of the sampling frequency divided by the number of discrete points The value is less than the starting frequency of the phase noise to be generated.

21. A computer program, including program instructions. When the program instructions are executed by a device for generating discrete domain phase noise, the device can execute the method described in any one of claims 1-10.

22. A carrier carrying the computer program of claim 21.