WO2016095683A1

WO2016095683A1 - Method and device for eliminating tdd noise

Info

Publication number: WO2016095683A1
Application number: PCT/CN2015/095699
Authority: WO
Inventors: 杨涛
Original assignee: 华为技术有限公司
Priority date: 2014-12-15
Filing date: 2015-11-26
Publication date: 2016-06-23
Also published as: CN105761726B; CN105761726A

Abstract

A method and device for eliminating TDD noise, which can eliminate TDD noise in a call made by a GSM standard mobile phone. The method comprises: when an amplitude value A _i of an audio signal at a preset frequency point is larger than a preset threshold B, adjusting the amplitude value A _i of the audio signal at the preset frequency point to be smaller than the threshold B, wherein the audio signal is a frequency domain signal, the preset frequency point comprises L frequency points in total, and the frequencies of the L frequency points are respectively if ₀, where f ₀ is 217 Hz and 1≤i≤L (101). The method is applicable to the technical field of audio.

Description

Method and device for eliminating TDD noise

This application claims priority to Chinese Patent Application No. 201410777658.3, filed on Dec. 15, 2014, entitled "A Method and Apparatus for Eliminating TDD Noise", the contents of the prior application file are hereby incorporated by reference. Combined in this application.

Technical field

The present invention relates to the field of audio technologies, and in particular, to a method and apparatus for eliminating TDD noise.

Background technique

Existing mobile phones of the Global System for Mobile Communication (GSM) system generally have time division duplex (English: Time Division Duplexing, TDD) noise during the call. The cause is GSM. The RF power amplifier of the mobile phone of the standard type is turned on every 217Hz, and it needs to consume a large current of 1.5A every time it is turned on. The large current consumption of 217Hz is the voltage drop of the power supply of 217Hz frequency, and the signal generated by the falling of the power supply voltage It is a noise signal and is called a TDD noise signal. The TDD noise signal is restored by the audio device to produce audible noise from the human ear.

The prior art improves the hardware so that there is no cross between the circuit composed of the RF power amplifier and the power supply and the circuit corresponding to the audio processing portion, and when the RF power amplifier operates, the circuit corresponding to the audio processing portion is not affected. , thereby suppressing TDD noise. However, with the above-described hardware improvement method, debugging is difficult and the circuit is complicated.

Summary of the invention

The embodiments of the present invention provide a method and an apparatus for eliminating noise, which solves the problem that the debugging of the prior art to eliminate TDD noise is difficult and the circuit is complicated.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

In a first aspect, an embodiment of the present invention provides a method for eliminating TDD noise, the method comprising:

When the amplitude value A _{i of} the audio signal at the preset frequency point is greater than the preset threshold value B, adjusting the amplitude value A _{i of} the audio signal at the preset frequency point to be less than the threshold value B, wherein The audio signal is a frequency domain signal, and the preset frequency points include a total of L frequency points, wherein the frequencies of the L frequency points are respectively if ₀ , f ₀ is 217 Hz, and 1 ≤ i ≤ L.

In a first possible implementation, in combination with the first aspect, the B is an amplitude value corresponding to the frequency domain f ₀ obtained under a preset condition, where the preset condition is to receive Or the volume of the device transmitting the audio signal is adjusted to a minimum, and by adjusting the transmit power of the RF power amplifier of the device, the obtained signal is a critical value of the signal heard by the human ear, and the signal is converted into the frequency domain. signal.

In a second possible implementation, in combination with the first aspect or the first possible implementation, the adjusting the amplitude value A _{i of} the audio signal at the preset frequency point to be less than the threshold value B specifically includes:

Obtaining the maximum value of k when kA _i <B, where k=b/2 ^a , 1≤b<2, a is a positive integer;

The amplitude value A _{i of} the audio signal at the preset frequency point is adjusted to k times A _i .

In a third possible implementation, in combination with the first aspect or the first possible implementation, the adjusting the amplitude value A _{i of} the audio signal at the preset frequency point to be less than the threshold value B specifically includes:

Adjusting the amplitude value A _{i of} the audio signal at the preset frequency point to c/2 ^2-i * k times of A _i , where 1≤c<2.

In a second aspect, an embodiment of the present invention provides an apparatus for eliminating TDD noise, where the apparatus includes: an adjustment unit;

The adjusting unit, configured to, when an audio signal at a predetermined frequency amplitude value greater than a preset threshold A _i B, and the audio signal is less than the predetermined frequency in the amplitude adjusting value A _i The threshold value B, wherein the audio signal is a frequency domain signal, the preset frequency points include a total of L frequency points, the frequencies of the L frequency points are respectively if ₀ , f ₀ is 217 Hz, 1 ≤ i ≤ L.

In a first possible implementation, in combination with the second aspect, the B is an amplitude value corresponding to the frequency domain f ₀ obtained under a preset condition, where the preset condition is to receive Or the volume of the device transmitting the audio signal is adjusted to a minimum, and by adjusting the transmit power of the RF power amplifier of the device, the obtained signal is a critical value of the signal heard by the human ear, and the signal is converted into the frequency domain. signal.

In a second possible implementation, in combination with the second aspect or the first possible implementation, the apparatus further includes: an acquiring unit;

The obtaining unit is configured to obtain a maximum value of k when kA _i <B, where k=b/2 ^a , 1≤b<2, and a is a positive integer;

The adjusting unit is specifically configured to: adjust an amplitude value A _{i of} the audio signal at the preset frequency point to k times of A _i .

In a third possible implementation, in combination with the second aspect or the first possible implementation, the apparatus further includes: an acquiring unit;

The adjusting unit is specifically configured to: adjust an amplitude value A _{i of} the audio signal at the preset frequency point to c/2 ^2-i * k times of A _i , where 1≤c<2.

Embodiments of the present invention provide a method and apparatus for eliminating TDD noise. When determining whether an audio signal received or transmitted is in a frequency domain, whether the amplitude value at a frequency point corresponding to a frequency of 217 Hz and its frequency multiplication is greater than a preset gate If the limit value is greater than, the amplitude value at the frequency point corresponding to the frequency of 217 Hz and its multiplication is compressed to be less than the threshold value, thereby eliminating TDD noise, thereby avoiding the prior art to eliminate TDD by hardware. Noise is difficult to debug, the workload is large, and the circuit is complicated.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic diagram of a method for eliminating TDD noise;

2 is a schematic diagram of another method for eliminating TDD noise;

3 is a schematic diagram of an apparatus for eliminating TDD noise;

Figure 4 is a schematic diagram of another apparatus for eliminating TDD noise.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In order to solve the problem that the debugging of the TDD noise is eliminated by the hardware, the workload is large, and the circuit is complicated, the embodiment of the present invention provides a method for eliminating TDD noise, and the method includes:

101. When the amplitude value A _{i of} the audio signal at the preset frequency point is greater than the preset threshold value B, adjust the amplitude value A _{i of} the audio signal at the preset frequency point to be less than the threshold value B. The audio signal is a frequency domain signal, and the preset frequency points include a total of L frequency points, wherein the frequencies of the L frequency points are respectively if ₀ , f ₀ is 217 Hz, and 1≤i≤L.

Specifically, the audio signal may be an uplink audio signal, that is, an audio signal sent by a mobile phone, or may be a downlink audio signal, that is, an audio signal received by a mobile phone. The audio signal is subjected to fast Fourier transform to obtain a frequency domain signal of the audio signal.

The principle generated by the TDD noise can be obtained. If TDD noise is present in the audio signal, the TDD noise is distributed at a frequency corresponding to a frequency of f ₀ =217 Hz and its multiplication. Theoretically, when there is TDD noise, the signal amplitude of the frequency point corresponding to f ₀ =217Hz is the largest, and the amplitude of the frequency of f ₀ , such as 2f ₀ , 3f ₀ ... nf ₀ , is sequentially decreased, but still higher than The amplitude at other frequencies.

That is, the frequency points corresponding to the frequency multiplications of f ₀ and f ₀ are the most concentrated frequency points of the TDD noise energy. If the signal strength at the frequency points is greater than the preset threshold value B, the audio signal can be judged. There is TDD noise, and if the signal strength at these frequencies is less than the preset threshold, it is determined that there is no TDD noise in the audio signal.

The B is an amplitude value of a frequency domain signal obtained under a preset condition at a frequency point corresponding to f ₀ , wherein the preset condition is to adjust a volume of a device that receives or transmits the audio signal to a minimum value, And by adjusting the transmit power of the RF power amplifier of the device, the obtained signal is a critical value of the signal heard by the human ear, and the signal is converted into a frequency domain signal.

It should be noted that the GSM mobile phone will generate TDD noise for both the uplink signal and the downlink signal. For example, the user 1 uses the GSM mobile phone, and the user 2 uses the other standard mobile phone, when the user 1 and the user 2 When making a call, the signal received by 1 and the signal received by User 2 will contain the TDD noise signal generated by the operation of the RF power amplifier of User 1's mobile phone.

Specifically, when the B is obtained, the mobile phone of the GSM standard, such as the mobile phone of the user 1, can be adjusted to the lowest value, and the radio frequency power amplifier of the mobile phone is set to the maximum emission. Power, obtain the signal sent by the GSM mobile phone at this time, determine whether the signal is a human audible signal, and if so, adjust the RF power amplifier of the GSM mobile phone until the obtained measured signal is audible to the human ear. The critical value of the signal, the measured signal is converted into a frequency domain signal, and the amplitude value at the 217 Hz frequency point is taken as the threshold value B.

The reason for setting the threshold is that when the size of the TDD noise generated by the GSM mobile phone is independent of other audio signals, the TDD noise generated when the RF power amplifier of the GSM mobile phone is at the maximum transmission power is the largest. Therefore, when the volume of the device that generates the TDD noise is minimized, the obtained signal is a TDD signal that does not include other voice signals, and the transmission power of the RF power amplifier of the device is adjusted from large to small until the obtained does not include The TDD noise signal of other speech signals is a critical value of the signal audible to the human ear, and the actually measured signal is converted into a frequency domain signal, and the amplitude value of the frequency domain signal at the 217 Hz frequency point is obtained as a critical value.

The audio signal is actually composed of a voice signal during talk and TDD noise, and the voice signal also has energy at 217 Hz and its multiple frequency, and the energy of the voice signal at the frequency point corresponding to the 217 Hz and its frequency multiplication is usually smaller than the gate. Limit value, when the energy of the audio signal at the frequency point corresponding to 217 Hz and its multiplication is greater than the threshold, it can be proved that TDD noise exists, and the amplitude value of the audio signal at 217 Hz and its multiple is adjusted to Less than the threshold value, the TDD noise signal is a signal that is inaudible to the human ear, thereby eliminating TDD noise.

Specifically, the preset L frequency points are frequency points of frequency f ₀ to frequency times of frequency F ₀ , by determining each frequency point of the L preset frequency points If the amplitude value is greater than the preset threshold value B, it can be determined whether the audio signal has TDD noise. Specifically, the value of L can be obtained according to the actual situation, which is not limited by the embodiment of the present invention.

If the amplitude value A _{i of} the audio signal is greater than the preset threshold B, the TDD noise is present in the audio signal, and the amplitude value of the L preset frequency points is greater than B. The amplitude of the frequency points is compressed and compressed to less than the threshold value, thereby eliminating TDD noise.

After eliminating the TDD noise, the audio signal is also converted into a time domain signal by Fourier inverse transform, and the audio signal is transmitted.

Certainly, if the amplitude values of the L preset frequency points are all less than the threshold value, determining that there is no TDD noise in the audio signal, the audio signal is converted into a time domain signal for transmission.

An embodiment of the present invention provides a method for eliminating TDD noise. When determining whether a received or transmitted audio signal is in a frequency domain, the frequency is 217 Hz and a frequency point corresponding to the frequency doubling thereof. Whether the amplitude value is greater than a preset threshold value, and if it is greater than, the amplitude value at the frequency point corresponding to the frequency 217 Hz and its frequency multiplication is compressed to be less than the threshold value, thereby eliminating TDD noise, thereby avoiding The prior art eliminates TDD noise by hardware, which is difficult to debug, large in workload, and complicated in circuit.

In order to solve the problem that the debugging of the TDD noise in the prior art is difficult, the workload is large, and the circuit is complicated, the embodiment of the present invention further provides a method for eliminating TDD noise, and the method includes :

201. When the amplitude value A _{i of the} audio signal at the preset frequency point is greater than the preset threshold value B, obtain a maximum value of k when kA _i <B, where k=b/2 ^a , 1≤b<2 , a is a positive integer.

Specifically, the k value can be obtained by the following process:

The amplitude value of the audio signal at the L frequency points is reduced by the same ratio under a preset rule to find the maximum k value under the rule. For example, the preset rule is to reduce the amplitude value of the audio signal at the L frequency points by k=b/2 ^a times, and b is a preset fixed value, specifically, 1≤b<2 , a is a variable, and a is a natural number. When the less than a preset threshold value increments from 1 until the audio signal amplitude values in the L frequencies are multiplied by the specific value of b / 2 ^a corresponding post, the b / 2 ^a The corresponding specific value is the k value to be obtained.

For example, b=1, when a is 1 or 2, that is, b/2 ^a is 1/2 or 1/4, the amplitude value of the audio signal at the L frequency points is multiplied by 1/2 or 1/4 is still greater than the preset threshold. When a is 3, that is, b/2 ^a is 1/8, the amplitude value of the audio signal at the L frequency points is multiplied by 1/8. If both are less than the preset threshold, then 1/8 is the value of k to be obtained.

Certainly, the frequency point corresponding to the amplitude value of the L frequency points may be found, and the amplitude value of the frequency point is compressed to a maximum k value smaller than the threshold value, where the k value is kA _i < The maximum value of k at B.

202. Adjust the amplitude value A _{i of} the audio signal at the preset frequency point to k times of A _i .

The amplitude values of the L frequency points are multiplied by k times such that the amplitude values of the L frequency points are all less than a threshold value, thereby eliminating TDD noise in the audio signal.

Further, from the theoretical analysis of the spectral characteristics, as the 217 Hz multiplier increases, the amplitude of the TDD noise at 217 octaves will decrease by a multiple of two. Specifically, the amplitude of the TDD noise at 217 Hz is M, and theoretically the amplitude of the TDD noise at the 2 times 217 Hz frequency point is 1/2 M..., and the amplitude at the frequency point corresponding to the 217 Hz of the n times is usually M. 1/2 ⁿ _- ¹ .

Then, in order to reduce the damage to the true degree of the audio signal, after obtaining the k value, the amplitude values of the frequency points corresponding to if ₀ are respectively multiplied by c/2 ^2-i *k, where 1≤c<2 It should be noted that the reason why the value range of c is selected in this way is to better remove the TDD noise. For example, at the 217 Hz frequency point, when k is 1/8, the amplitude value at the 217 Hz frequency point can be compressed to It is smaller than the threshold, but it is still close to the threshold after compression. Therefore, the amplitude value at the 217 Hz frequency can be compressed to 1/10 of the original value, that is, 1 ≤ c < 2.

For example, when the value of k is obtained by step 202 and the value of k is 1/8, and c/2*k=1/10, when i=1, the amplitude value of the frequency point of f ₀ =217 Hz is compressed to the original 1 /10, assuming that the amplitude value of the TDD noise at the 217 Hz frequency is M, and the amplitude value of the speech signal is A, the amplitude value after compression is 1/10 (A+M), that is, the TDD noise at the 217 Hz frequency is compressed. For the original 1/10, the speech signal at the 217 Hz frequency is compressed to 1/10 of the original.

At the frequency point corresponding to 2 times 217 Hz, i=2, then c/2 ^2-i *k=1/5, that is, the amplitude value at the frequency point corresponding to 2 times 217 Hz is compressed to the original 1/. 5, assuming that the amplitude of the speech signal at 2 times the 217 Hz frequency is B, and the TDD noise is 1/2 M, then the amplitude after compression is 1/5 (1/2M+B)=1/10M+1/5B That is, the TDD noise is compressed to 1/10 of the original, which is the same as the 217 Hz frequency, but the speech signal is only compressed to 1/5 of the original, thereby relatively ensuring the authenticity of the speech signal.

After the TDD noise is cancelled, the audio signal is also converted into a time domain signal by inverse Fourier transform, and the audio signal is transmitted.

The embodiment of the invention provides a method for eliminating TDD noise. When determining whether the received or transmitted audio signal is in the frequency domain, whether the amplitude value at the frequency corresponding to the frequency of 217 Hz and its multiplication is greater than a preset threshold If it is greater than, the amplitude value at the frequency point corresponding to the frequency of 217 Hz and its multiplication is compressed to be less than the threshold value, thereby eliminating the TDD noise, thereby avoiding the prior art to eliminate the TDD noise band by hardware. The debugging is difficult, the workload is large, and the circuit is complicated.

In order to solve the problem that the debugging of the TDD noise in the prior art is difficult, the workload is large, and the circuit is complicated, the embodiment of the present invention further provides a device for eliminating TDD noise, and the device includes : adjustment unit 301;

The adjusting unit 301, when the audio signal values for A _i is greater than the preset threshold value B at a predetermined frequency amplitude value of the audio signal A _i in the predetermined frequency is adjusted to less than the amplitude The threshold value B, wherein the audio signal is a frequency domain signal, and the preset frequency points include a total of L frequency points, wherein the frequencies of the L frequency points are respectively if ₀ and f ₀ is 217 Hz, 1 ≤ i ≤ L.

Specifically, the B is an amplitude value corresponding to the frequency domain f _{0 obtained} under the preset condition, wherein the preset condition is that the volume of the device that receives or transmits the audio signal is adjusted to The lowest, and by adjusting the transmit power of the RF power amplifier of the device, the obtained signal is the threshold of the signal heard by the human ear and converts the signal into a frequency domain signal.

Specifically, in conjunction with FIG. 3, the device further includes: an obtaining unit 302;

The obtaining unit 302 is configured to obtain a maximum value of k when kA _i <B, where k=b/2 ^a , 1≤b<2, and a is a positive integer;

The adjusting unit 301 is specifically configured to: adjust the amplitude value A _{i of} the audio signal at the preset frequency point to k times of A _i .

The adjusting unit 301 is specifically configured to: adjust an amplitude value A _{i of} the audio signal at the preset frequency point to c/2 ^2-i * k times of A _i , where 1≤c<2.

For a detailed technical feature of the embodiment of the present invention, reference may be made to the embodiment of the method corresponding to FIG. 1 and FIG.

The embodiment of the invention provides a device for eliminating TDD noise. The device determines whether the amplitude value at a frequency point corresponding to the frequency of 217 Hz and its frequency multiplication is greater than a preset gate by determining whether the received or transmitted audio signal is in the frequency domain. If the limit value is greater than, the amplitude value at the frequency point corresponding to the frequency of 217 Hz and its multiplication is compressed to be less than the threshold value, thereby eliminating TDD noise, thereby avoiding the prior art to eliminate TDD by hardware. Noise is difficult to debug, the workload is large, and the circuit is complicated.

In order to solve the problem that the debugging of the TDD noise is eliminated by the hardware, the workload is large, and the circuit is complicated, the embodiment of the present invention further provides a device for eliminating TDD noise, and the device includes a processor 401, a bus 402 and a memory 403, wherein the processor 401 acquires an instruction in the memory 403 through the bus 402 to use to:

The processor 401 is specifically configured to:

Optionally, the processor 401 is specifically configured to:

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A method for eliminating TDD noise, characterized in that the method comprises:

When the amplitude value A i of the audio signal at the preset frequency point is greater than the preset threshold value B, adjusting the amplitude value A i of the audio signal at the preset frequency point to be less than the threshold value B, wherein The audio signal is a frequency domain signal, and the preset frequency points include a total of L frequency points, wherein the frequencies of the L frequency points are respectively if 0 , f 0 is 217 Hz, and 1 ≤ i ≤ L.
The method according to claim 1, wherein the B is an amplitude value corresponding to a frequency domain signal obtained under a preset condition at a frequency point f 0 , wherein the preset condition is to receive or transmit The volume of the device of the audio signal is adjusted to a minimum, and by adjusting the transmit power of the RF power amplifier of the device such that the obtained signal is a critical value of the signal heard by the human ear and converting the signal into a frequency domain signal.
The method according to claim 1 or 2, wherein the adjusting the amplitude value A i of the audio signal at the preset frequency point to be less than the threshold value B comprises:

Obtaining the maximum value of k when kA i <B, where k=b/2 a , 1≤b<2, a is a positive integer;

The amplitude value A i of the audio signal at the preset frequency point is adjusted to k times A i .
The method according to claim 1 or 2, wherein the adjusting the amplitude value A i of the audio signal at the preset frequency point to be less than the threshold value B comprises:

Obtaining the maximum value of k when kA i <B, where k=b/2 a , 1≤b<2, a is a positive integer;

Adjusting the amplitude value A i of the audio signal at the preset frequency point to c/2 2-i * k times of A i , where 1≤c<2.
A device for eliminating TDD noise, characterized in that the device comprises: an adjustment unit;

The adjusting unit, configured to, when an audio signal at a predetermined frequency amplitude value greater than a preset threshold A i B, and the audio signal is less than the predetermined frequency in the amplitude adjusting value A i The threshold value B, wherein the audio signal is a frequency domain signal, the preset frequency points include a total of L frequency points, the frequencies of the L frequency points are respectively if 0 , f 0 is 217 Hz, 1 ≤ i ≤ L.
The device according to claim 5, wherein the B is an amplitude value corresponding to the frequency domain f 0 obtained under a preset condition, wherein the preset condition is to receive or send The volume of the device of the audio signal is adjusted to a minimum, and by adjusting the transmit power of the RF power amplifier of the device such that the obtained signal is a critical value of the signal heard by the human ear and converting the signal into a frequency domain signal.
The device according to claim 5 or 6, wherein the device further comprises: Acquisition unit

The obtaining unit is configured to obtain a maximum value of k when kA i <B, where k=b/2 a , 1≤b<2, and a is a positive integer;

The adjusting unit is specifically configured to: adjust an amplitude value A i of the audio signal at the preset frequency point to k times of A i .
The device according to claim 5 or 6, wherein the device further comprises: an acquisition unit;

The obtaining unit is configured to obtain a maximum value of k when kA i <B, where k=b/2 a , 1≤b<2, and a is a positive integer;

The adjusting unit is specifically configured to: adjust an amplitude value A i of the audio signal at the preset frequency point to c/2 2-i * k times of A i , where 1≤c<2.