CN1946101A - Method and device for realizing mobile terminal audio signal self adaption - Google Patents
Method and device for realizing mobile terminal audio signal self adaption Download PDFInfo
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- CN1946101A CN1946101A CN 200610137936 CN200610137936A CN1946101A CN 1946101 A CN1946101 A CN 1946101A CN 200610137936 CN200610137936 CN 200610137936 CN 200610137936 A CN200610137936 A CN 200610137936A CN 1946101 A CN1946101 A CN 1946101A
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Abstract
This invention discloses a method and a device for realizing adaptation of mobile terminal audio signals, which includes: obtaining the voltage of the audio signal sent to the audio power amplifier by said analog baseband chip and attenuating said audio signals when identifying that the voltage of the audio signal is over the preset threshold one and sending the attenuated signal to the amplifier. This invention also discloses a mobile terminal and a device for realizing it.
Description
Technical field
The present invention relates to communication technical field, relate in particular to a kind of method and device of realizing mobile terminal audio signal self adaption.
Background technology
Ubiquity and is uttered long and high-pitched sounds and the audio frequency power amplifier problem of dtmf distortion DTMF in the communication process, and in trunking communication, mobile phone is in the hand-free call state usually, and it is particularly outstanding with the audio frequency power amplifier problem of dtmf distortion DTMF to utter long and high-pitched sounds.
In the trunking communication utter long and high-pitched sounds and audio frequency power amplifier distortion producing method be divided into two kinds: a kind of be the point exhale under the hands-free state, because the loud speaker output sound is big, and spacing is short between loud speaker and the receiver, be easy to be caught from the sound of hearer's loud speaker output by hearer's receiver, send to the speaker then, the sound of speaker's loud speaker output is caught by speaker's receiver again, send to the hearer, so just formed a positive feedback, go round and begin again, the power amplifier of both sides' mobile phone just enters saturation condition, and distortion takes place in power amplifier output, and then generation is uttered long and high-pitched sounds; Another is under the group calling state, and when hearer and speaker's close together, the sound of exporting from hearer's loud speaker is easy to just be caught by speaker's receiver, pass to the hearer then again, also formed a positive feedback, go round and begin again, power amplifier generation distortion, and then also generation is uttered long and high-pitched sounds.
Referring to Fig. 1, be the system configuration schematic diagram of existing techniques in realizing to audio signal control.
Utter long and high-pitched sounds and the audio frequency power amplifier problem of dtmf distortion DTMF with regard to its essence, be because the audio signal of Analog Baseband chip output is strong excessively, after causing audio signal to be input to back level audio-frequency power amplifier, cause the saturated or self-excitation of audio-frequency power amplifier, the audio-frequency power amplifier output signal has produced nonlinear distortion.
At present, the prior art scheme can't solve uttering long and high-pitched sounds and the problem of audio frequency power amplifier distortion in the communication process.
Summary of the invention
The embodiment of the invention provides a kind of method and device of realizing mobile terminal audio signal self adaption, in order to solve uttering long and high-pitched sounds and the problem of audio frequency power amplifier distortion in the communication process.
The method of the embodiment of the invention is applied in portable terminal, and the Analog Baseband chip sends in the process of audio signal to audio-frequency power amplifier, and this method comprises:
Obtain the voltage of the audio signal that described Analog Baseband chip sends to audio-frequency power amplifier, when the voltage that identifies described audio signal surpasses default threshold voltage, described audio signal is decayed;
Audio signal after the described decay is sent to described audio-frequency power amplifier.
The portable terminal of the embodiment of the invention comprises Analog Baseband chip and audio-frequency power amplifier, and this portable terminal also comprises:
The audio signal self adaption device is used for audio signal being decayed, and the audio signal after the described decay being sent to described audio-frequency power amplifier when the voltage of the audio signal of described Analog Baseband chip output surpasses default threshold voltage.
The device of the embodiment of the invention comprises:
The audio signal peak detector is used for the voltage magnitude characteristic according to the audio signal of Analog Baseband chip output, and obtains corresponding direct voltage;
The threshold voltage comparator is used for more described direct voltage and default threshold voltage, when described direct voltage surpasses default threshold voltage, triggers controllable attenuator work;
Controllable attenuator decays to audio signal, and the back signal of will decaying is exported to audio-frequency power amplifier.
The embodiment of the invention, when surpassing default threshold voltage,, realize the control of portable terminal to audio signal to the technical scheme that described audio signal decays by voltage when audio signal, avoid uttering long and high-pitched sounds and the problem of audio frequency power amplifier distortion in the communication process, improved output tonequality.
Description of drawings
Fig. 1 is a system configuration schematic diagram of the prior art;
Fig. 2 is the schematic flow sheet of the inventive method embodiment;
Fig. 3 is the structural representation of apparatus of the present invention embodiment;
Fig. 4 is the structural representation of portable terminal embodiment of the present invention;
Fig. 5 is the electrical block diagram of system embodiment of the present invention;
Fig. 6 is the output waveform schematic diagram when input audio signal is 300Hz in the specific embodiments of the invention;
Fig. 7 is the output waveform schematic diagram when input audio signal is 1KHz in the specific embodiments of the invention;
Fig. 8 is the output waveform schematic diagram when input audio signal is 3KHz in the specific embodiments of the invention;
Fig. 9 is the output waveform schematic diagram when input audio signal is 10KHz in the specific embodiments of the invention.
Embodiment
In the technical scheme that the embodiment of the invention provides, obtain the voltage magnitude characteristic of audio signal by the audio signal peak detector, and the voltage magnitude characteristic is converted to corresponding direct voltage, by the threshold voltage comparator described direct voltage and the threshold voltage of presetting are compared, when direct voltage during greater than threshold voltage, the output high level, the work of triggering controllable attenuator, described audio signal is decayed, after audio signal after the decay is passed through the voltage amplification of audio voltage amplifier again, export to the user through audio-frequency power amplifier and loud speaker respectively, make portable terminal reach self adaptation to audio signal, realization is to the control of audio signal, avoids uttering long and high-pitched sounds and the problem of audio frequency power amplifier distortion in the communication process, improved output tonequality.
Described audio signal self adaption, be exactly in the hand-free call process, one cover dynamic detection algorithm or circuit is set on the down link of user terminal, detect the fluctuation of audio signal, in case fluctuation surpasses default threshold value, just reduce the yield value of down link, make system reach self adaptation to audio signal, stop the formation of positive feedback, suppress to utter long and high-pitched sounds and the generation of audio frequency power amplifier distortion.
Referring to Fig. 2, the inventive method embodiment is applied in portable terminal, and the Analog Baseband chip sends in the process of audio signal to audio-frequency power amplifier, and this method specifically may further comprise the steps:
S201, obtain the voltage of the audio signal of Analog Baseband chip output;
Described audio signal is a simulated audio signal;
Obtain the voltage magnitude characteristic of described audio signal by the audio signal peak detector, and obtain corresponding direct voltage, and this direct voltage is sent to voltage comparator;
Before the voltage of the audio signal of obtaining described Analog Baseband chip output, can also comprise: the audio signal of described Analog Baseband chip output is carried out voltage amplification; So, the voltage magnitude characteristic of obtaining the audio signal of described Analog Baseband chip output is: the voltage magnitude characteristic of obtaining the audio signal after the voltage amplification;
Therefore, described audio voltage amplifier can link to each other with the audio signal peak detector, be used for the audio signal of Analog Baseband chip output is carried out processing and amplifying, audio signal after the described processing and amplifying is sent to described audio signal peak detector, audio signal after described processing and amplifying reaches the cleaning door of audio signal peak detector and prescribes a time limit, when promptly this audio signal can produce power amplification distortion, the audio signal peak detector is started working, obtain the voltage magnitude characteristic of the audio signal after the described processing and amplifying, and obtain corresponding direct voltage, this direct voltage is sent to voltage comparator;
S202, when the voltage of audio signal during greater than threshold voltage, audio signal is decayed, and the audio signal after the described decay is sent to audio-frequency power amplifier;
By voltage comparator described direct voltage and the threshold voltage that sets in advance are compared,, audio signal is decayed, and the audio signal after will decaying sends to the audio voltage amplifier when described direct voltage during greater than described threshold voltage;
Wherein, can realize decay by controllable attenuator to audio signal;
Described threshold voltage is that the requirement according to the descending gain of user terminal sets in advance;
Audio signal after the described decay is sent to described audio-frequency power amplifier can also be comprised before: the audio signal after the described decay is carried out processing and amplifying; So, the audio signal after the described decay being sent to described audio-frequency power amplifier is: will send to audio-frequency power amplifier through the audio signal after the described decay of processing and amplifying;
Export to the user through audio-frequency power amplifier and loud speaker respectively through the audio signal after the described decay of processing and amplifying.
To sum up, the effect of described audio voltage amplifier is: enlarge the scope of input, promote audio-frequency power amplifier and the work of audio signal peak detector simultaneously;
For example: under the situation of not using the audio voltage amplifier, the audio-frequency power amplifier multiplication factor is 10, when input signal is 500mV, audio-frequency power amplifier is saturation distortion just, but, for the audio signal peak detector, the small-signal of 500mV is not enough to allow the work of audio signal peak detector, need be higher than 700mV, could allow the work of audio signal peak detector, like this for the input signal between 500mV～700mV, system just can't normally control, if add the audio voltage amplifier, same whole system voltage gain still is set to 10, and different is, this moment, the audio-frequency power amplifier multiplication factor can be set to 7, the voltage amplifier multiplication factor is set to 1.43, and when input 500mV signal, the signal after the amplification is 715mV so, audio-frequency power amplifier can produce saturation distortion, the input of audio signal peak detector has had the input of 715mV signal, and the audio signal peak detector can operate as normal, realizes the control to audio signal;
If controllable attenuator is a two-stage, one-level attenuator attenuation coefficient is 1, secondary attenuator attenuation coefficient is 0.8, when input was the 500mV signal, the one-level attenuator was started working so, and the gain of whole system is so: 1.43*7*1=10.01, under this critical condition, according to described input signal and gain, obtain audio-frequency power amplifier and be output as 5V, just undistorted; If one-level attenuator attenuation coefficient is 1, secondary attenuator attenuation coefficient is 0.8, so when input is the 600mV signal, the two-stage attenuator is started working simultaneously, the gain of whole system is so: 1.43*7*1*0.8=8.008, under this state, audio-frequency power amplifier is output as 4.8048V, also can distortion;
Described to the audio signal voltage amplification multiple, can and determine according to the voltage magnitude of audio signal the multiple of audio signal power amplification, excessive when the voltage magnitude of audio signal, when making the audio frequency power amplifier distortion, then suitably reduce the audio signal voltage amplification multiple.Otherwise,, in the time of can not causing the audio frequency power amplifier distortion, then can suitably improve the audio signal voltage amplification multiple when the voltage magnitude of audio signal is very little;
Realize real-time control by above-mentioned three steps, make portable terminal reach self adaptation, suppress to utter long and high-pitched sounds and the generation of audio frequency power amplifier distortion audio signal to audio signal.
Referring to Fig. 3, the structural representation of the mobile terminal audio signal self adaption device that provides for the embodiment of the invention, the system that provides in the embodiment of the invention comprises audio signal self adaption device 301;
Described audio signal self adaption device 301 comprises: controllable attenuator 3011, audio voltage amplifier 3012, audio signal peak detector 3013, threshold voltage comparator 3014 and external interface unit 3015.
Wherein, controllable attenuator 3011 is idle when beginning received audio signal most, just the audio signal that is obtained is transmitted to audio voltage amplifier 3012; After the voltage amplification of 3012 pairs of audio signals of audio voltage amplifier, if the audio signal of input audio signal self-reacting device 301 is stronger audio signals, can cause power amplification distortion, then can trigger 3013 work of audio signal peak detector, if the audio signal of input audio signal self-reacting device 301 is more weak audio signals, can not cause power amplification distortion, then audio signal peak detector 3013 can not worked, and audio voltage amplifier 3012 is directly with the audio signal output after the voltage amplification;
Audio signal peak detector 3013, obtain the voltage magnitude characteristic of audio signal, the voltage magnitude characteristic is converted into corresponding direct voltage, audio signal peak detector 3013 needs good convergence, can be in the time that people's ear can be discovered, rule of thumb, this time is generally 20ms, and the voltage magnitude feature extraction of audio signal is come out.
Described default threshold voltage can be looked the requirement of the descending gain of user terminal, adjusts flexibly, requires described gain high, then default threshold voltage is provided with high; Otherwise, require described gain low, then default threshold voltage is provided with low.
Controllable attenuator 3011, when threshold voltage comparator 3014 output high level, controllable attenuator 3011 begins audio signal is decayed, audio signal through controllable attenuator 3011 decay, export after the voltage amplification through audio voltage amplifier 3012 again, thereby avoided uttering long and high-pitched sounds and the audio frequency power amplifier distortion in the communication process; When threshold voltage comparator 3014 output low levels, controllable attenuator 3011 does not decay to audio signal, and directly output after the voltage amplification of 3012 pairs of audio signals of audio voltage amplifier can not produce yet and utter long and high-pitched sounds and the audio frequency power amplifier distortion this moment;
Wherein, the user can be by described external interface unit 3015, the value of threshold voltage is set, the multiple value that audio signal is decayed and the multiple value of audio signal being carried out voltage amplification.
Through above-mentioned processing, realized control to the audio signal of input, the audio signal of output can not cause utters long and high-pitched sounds and the audio frequency power amplifier distortion.
More than design only is provided with one-level threshold voltage comparator and the one-level controllable attenuator is controlled, refined control more if desired, and the thresholding number that can be by increasing the threshold voltage comparator and the progression of controllable attenuator be realized.
Referring to Fig. 4, the portable terminal that the embodiment of the invention provides comprises: Analog Baseband chip 401, audio signal self adaption device 402, audio-frequency power amplifier 403 and loud speaker 404;
Described audio signal self adaption device 402 comprises: controllable attenuator 4021, audio voltage amplifier 4022, audio signal peak detector 4023, threshold voltage comparator 4024 and external interface unit 4025.
Wherein, the user can be by described external interface unit 4025, the value of threshold voltage is set, the multiple value that audio signal is decayed and the multiple value of audio signal being carried out voltage amplification.
Realize the physical circuit figure of this system, as shown in Figure 5, V1 is the simulated audio signal source among the figure, by its parameter is set, can simulate the audio signal that different frequency takes place; Attenuator is a controllable attenuator, and its output can be the audio signal that the audio signal that V1 exports is decayed, and whether controls its work by the output signal of U6A, and U6A is a voltage comparator; U1A is an audio signal amplifier, and the Attenuator output signal is suitably amplified, and in the design, is realized by a slice LM833; Peak Detector is a peak detector, audio signal to U1A output is carried out detection, output can reflect that the d. c. voltage signal of audio signal peak feature is to back step voltage comparator U6A, U6A is realized by a slice LM339, finish comparison to the threshold voltage of peak detector output signal and setting, when the voltage of peak detector output signal during greater than threshold voltage, U6A exports high level signal, be about 4V, the concrete supply power voltage of value viewing system of this high level signal and deciding generally requires greater than 2.1V.Controllable attenuator is started working after receiving described high level signal, and when peak detector output signal voltage during less than threshold voltage, U6A output low level signal is about 0V, and controllable attenuator does not decay to signal.
The simulated audio signal source imports 300Hz, 1KHz, 3KHz respectively, when the 10KHz signal carries out emulation, obtain respectively as Fig. 6, Fig. 7, Fig. 8 and waveform shown in Figure 9, wherein, dc is the signal of peak detector PeakDetector output, as seen through after the discharging and recharging of several cycles, the dc signal is tending towards exporting a direct current signal; Gain_con is the signal of voltage comparator U6A output, and this signal is controlled by dc, and after dc surpassed default threshold voltage, gain_con exported high level signal; In1 is the signal of simulated audio signal source output; In2 is the signal of controllable attenuator Attenuator output, and when gain_con output high level, controllable attenuator is unlocked, and reduces the signal amplitude of in2, and when the gain_com output low level, controllable attenuator is closed; Out is the output signal of audio signal amplifier U1A.
To sum up, in 20ms, be that people's ear is in the time that can discover, described circuit can be realized the mobile communication audio signal is carried out self adaptation, the frequency range of this audio signal is 300Hz to 3400Hz generally speaking, avoid uttering long and high-pitched sounds and the problem of audio frequency power amplifier distortion in the communication process, improved output tonequality.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.
Claims (13)
1, a kind of method that realizes mobile terminal audio signal self adaption is applied in portable terminal, and the Analog Baseband chip sends in the process of audio signal to audio-frequency power amplifier, it is characterized in that this method comprises:
Obtain the voltage of the audio signal that described Analog Baseband chip sends to audio-frequency power amplifier, when the voltage that identifies described audio signal surpasses default threshold voltage, described audio signal is decayed;
Audio signal after the described decay is sent to described audio-frequency power amplifier.
2, the method for claim 1 is characterized in that, the described step of obtaining the voltage of audio signal further comprises:
Obtain the voltage magnitude characteristic of the audio signal of described Analog Baseband chip output; And obtain and the corresponding direct voltage of described voltage magnitude characteristic, with the voltage of described direct voltage as described audio signal.
3, method as claimed in claim 2 is characterized in that, described method also comprises:
Obtained described Analog Baseband chip before the voltage of the audio signal that audio-frequency power amplifier sends: described Analog Baseband chip is carried out voltage amplification to the audio signal that audio-frequency power amplifier sends;
Correspondingly, the voltage magnitude characteristic of obtaining the audio signal of described Analog Baseband chip output further refers to: the voltage magnitude characteristic of obtaining the audio signal after the voltage amplification.
4, the method for claim 1 is characterized in that, described method also comprises:
Audio signal after the described decay is sent to before the described audio-frequency power amplifier: the audio signal after the described decay is carried out processing and amplifying;
Correspondingly, the audio signal after the described decay being sent to described audio-frequency power amplifier further refers to: will send to audio-frequency power amplifier through the audio signal after the described decay of processing and amplifying.
5, a kind of portable terminal comprises Analog Baseband chip and audio-frequency power amplifier, it is characterized in that, this portable terminal also comprises:
The audio signal self adaption device is used for audio signal being decayed, and the audio signal after the described decay being sent to described audio-frequency power amplifier when the voltage of the audio signal of described Analog Baseband chip output surpasses default threshold voltage.
6, portable terminal as claimed in claim 5 is characterized in that, described audio signal self adaption device comprises:
The audio signal peak detector is used for the voltage magnitude characteristic according to the audio signal of Analog Baseband chip output, obtains corresponding direct voltage;
The threshold voltage comparator is used for more described direct voltage and default threshold voltage, when described direct voltage surpasses default threshold voltage, triggers controllable attenuator work;
Controllable attenuator decays to audio signal, and the back signal of will decaying is exported to audio-frequency power amplifier.
7, portable terminal as claimed in claim 6, it is characterized in that, described audio signal self adaption device also comprises the audio voltage amplifier, be used for the audio signal of Analog Baseband chip output is carried out voltage amplification, and the audio signal after will amplifying sends to described audio signal peak detector;
Described audio signal peak detector is used for the voltage magnitude characteristic according to the audio signal after the described amplification, obtains corresponding direct voltage.
8, portable terminal as claimed in claim 7, it is characterized in that, described audio voltage amplifier also is used for the audio signal of described controllable attenuator output is carried out voltage amplification, and the audio signal after the described voltage amplification is sent to audio-frequency power amplifier.
9, portable terminal as claimed in claim 8, it is characterized in that, described audio signal self adaption device also comprises external interface unit, is used to be provided with the value of threshold voltage, the multiple value that audio signal is decayed and the multiple value of audio signal being carried out voltage amplification.
10, a kind of device of realizing mobile terminal audio signal self adaption is characterized in that, this device comprises:
The audio signal peak detector is used for the voltage magnitude characteristic according to the audio signal of Analog Baseband chip output, and obtains corresponding direct voltage;
The threshold voltage comparator is used for more described direct voltage and default threshold voltage, when described direct voltage surpasses default threshold voltage, triggers controllable attenuator work;
Controllable attenuator decays to audio signal, and the back signal of will decaying is exported to audio-frequency power amplifier.
11, device as claimed in claim 10, it is characterized in that, this device also comprises the audio voltage amplifier, be used for the audio signal of Analog Baseband chip output is carried out voltage amplification, and the audio signal after will amplifying sends to described audio signal peak detector;
Described audio signal peak detector is used for the voltage magnitude characteristic according to the audio signal after the described amplification, obtains corresponding direct voltage.
12, device as claimed in claim 11 is characterized in that, described audio voltage amplifier also is used for the audio signal of described controllable attenuator output is carried out voltage amplification, and the audio signal after the described voltage amplification is sent to audio-frequency power amplifier.
13, device as claimed in claim 12 is characterized in that, this device also comprises external interface unit, is used to be provided with the value of threshold voltage, the multiple value that audio signal is decayed and the multiple value of audio signal being carried out voltage amplification.
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| CN 200610137936 CN1946101A (en) | 2006-10-31 | 2006-10-31 | Method and device for realizing mobile terminal audio signal self adaption |
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| CN 200610137936 CN1946101A (en) | 2006-10-31 | 2006-10-31 | Method and device for realizing mobile terminal audio signal self adaption |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101895870A (en) * | 2010-03-23 | 2010-11-24 | 中兴通讯股份有限公司 | Silence recognition device for mobile phone, mobile phone de-noising method and system thereof in silence mode |
| CN101527543B (en) * | 2008-03-06 | 2011-08-24 | 原景科技股份有限公司 | Audio system capable of suppressing switch noise and audio amplifier |
| CN102271189A (en) * | 2011-08-17 | 2011-12-07 | 惠州Tcl移动通信有限公司 | Mobile phone and distortion processing method thereof |
| CN102332282A (en) * | 2011-07-20 | 2012-01-25 | 深圳市君兰电子有限公司 | Performance detection method and system for DVD modules |
| WO2017000772A1 (en) * | 2015-06-30 | 2017-01-05 | 芋头科技（杭州）有限公司 | Front-end audio processing system |
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2006
- 2006-10-31 CN CN 200610137936 patent/CN1946101A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101527543B (en) * | 2008-03-06 | 2011-08-24 | 原景科技股份有限公司 | Audio system capable of suppressing switch noise and audio amplifier |
| CN101895870A (en) * | 2010-03-23 | 2010-11-24 | 中兴通讯股份有限公司 | Silence recognition device for mobile phone, mobile phone de-noising method and system thereof in silence mode |
| CN102332282A (en) * | 2011-07-20 | 2012-01-25 | 深圳市君兰电子有限公司 | Performance detection method and system for DVD modules |
| CN102271189A (en) * | 2011-08-17 | 2011-12-07 | 惠州Tcl移动通信有限公司 | Mobile phone and distortion processing method thereof |
| WO2017000772A1 (en) * | 2015-06-30 | 2017-01-05 | 芋头科技（杭州）有限公司 | Front-end audio processing system |
| CN106328154A (en) * | 2015-06-30 | 2017-01-11 | 芋头科技（杭州）有限公司 | Front-end audio processing system |
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