The utility model content
In order to improve the hand-free call quality when the multi-user shared cellular phone machine, the utility model embodiment provides a kind of handfree circuit and terminal.Said technical scheme is following:
On the one hand, a kind of handfree circuit is provided, said handfree circuit comprises: at least two Mikes, gain controller, mixer, echo canceler circuit, radio communication audio signal interface;
Wherein, Said gain controller comprises the input multiplexer corresponding with each Mike; The input of the input channel corresponding with said Mike links to each other in said each Mike and the said gain controller; The output of said gain controller links to each other with the first input end of said mixer; The output of said mixer links to each other with the input of said radio communication audio signal interface, and the output of said radio communication audio signal interface connects the input of said echo canceler circuit, and the output of said echo canceler circuit connects second input of said mixer.
On the other hand, a kind of terminal is provided, said terminal comprises: handfree circuit, said handfree circuit comprise at least two Mikes, gain controller, mixer, echo canceler circuit, radio communication audio signal interface;
Wherein, Said gain controller comprises the input multiplexer corresponding with each Mike; The input of the input channel corresponding with said Mike links to each other in said each Mike and the said gain controller; The output of said gain controller links to each other with the first input end of said mixer; The output of said mixer links to each other with the input of said radio communication audio signal interface, and the output of said radio communication audio signal interface connects the input of said echo canceler circuit, and the output of said echo canceler circuit connects second input of said mixer.
The beneficial effect that the technical scheme that the utility model embodiment provides is brought is: adopt the input of loquacity tube; Improve and send words signal to noise ratio and definition; Solve sound effect and spokesman from the problem that the phone distance is inversely proportional to, be applicable to the scene of multi-user shared wireless telephone call.
Embodiment
For the purpose, technical scheme and the advantage that make the utility model is clearer, will combine accompanying drawing that the utility model execution mode is done to describe in detail further below, but the utility model is not limited to following embodiment.
Embodiment 1
Referring to Fig. 1, the utility model provides a kind of handfree circuit, and handfree circuit comprises: at least two Mikes (MIC1, MIC2), gain controller 101, mixer 102, echo canceler circuit 103, radio communication audio signal interface 104;
Wherein, Gain controller 101 comprises the input multiplexer corresponding with Mike; The input of the input channel corresponding with Mike links to each other in each Mike and the gain controller; The output of gain controller 101 links to each other with the first input end of mixer 102; The output of mixer 102 links to each other with the input of radio communication audio signal interface 104, and the output of radio communication audio signal interface 104 connects the input of echo canceler circuit 104, and the output of echo canceler circuit 104 connects second input of mixer 102.
The beneficial effect that the utility model technical scheme is brought is: adopt the input of loquacity tube, improve and send words signal to noise ratio and definition, solved sound effect and spokesman from the problem that the phone distance is inversely proportional to, be applicable to the scene of multi-user shared wireless telephone call.
Embodiment 2
Referring to Fig. 2, present embodiment provides a kind of handfree circuit, comprising: MIC1, MIC2, MIC3, gain controller 201, mixer 202, echo canceler circuit 203, radio communication communication audio signaling interface 204; Wherein, Gain controlling 201 devices comprise the input multiplexer corresponding with each Mike; The input of the input channel corresponding with Mike links to each other in each Mike and the gain controller 201; The output of gain controller 201 links to each other with the first input end of mixer 202; The output of mixer 202 links to each other with the input of radio communication audio signal interface 204, and the output of radio communication audio signal interface 204 connects the input of echo canceler circuit, and the output of echo canceler circuit connects second input of mixer 202.Each Mike sends to the voice signal that receives the input of the input channel in its corresponding gain controller; After gain controller is handled voice signal; Voice signal after its processing is sent to mixer; Mixer is handled the signal of the gain controller input that receives, and the signal after handling is outputed to the radio communication audio signal interface, and the signal of exporting from the radio communication COBBAIF transfers to echo canceler circuit; Carry out subtraction from the signal of echo canceler circuit output and the receipts words signal of mixer output, to balance out this locality receipts words that Mike receives.
Referring to Fig. 2, alternatively, in the present embodiment, handfree circuit also comprises: the hand switch corresponding respectively with Mike, hand switch 1, hand switch 2, hand switch 3; Wherein, Wherein, MIC1, MIC2, MIC3 represent to import a plurality of microphones of connection, and these microphones pass through separately independently switch insertion gain controller; Gain controller has the input amplifier of a plurality of controllable gains, and each the road signal to input amplifies and addition respectively.The user place can be manually switched to the MIC open mode through the switch of MIC side when needs are made a speech; In the time need not making a speech, can switch cut out; Close the function of radio receiver of MIC this moment; Thereby guarantee that MPTY is clear continuous, effectively reduce unhelpful background noise, improve hands-free communication effect.
Further; Referring to Fig. 3; In the present embodiment; With the input channel corresponding with MIC1 is that example describes, and this input channel comprises: input amplifier 1, amplitude voltage transformation module 1, peak value keep delay unit 1, voltage-controlled reverse AGC (Automatic Gain Control, automatic gain control) amplifier 1; Wherein, First output of input amplifier 1 links to each other with an end of amplitude voltage transformation module 1; The other end of amplitude voltage transformation module 1 keeps an end of delay unit 1 to link to each other with peak value; The other end that peak value keeps delay unit 1 links to each other with a end except that the AGC amplifier of this input channel input channel of road; Simultaneously second output of input amplifier 1 links to each other with the first input end of voltage-controlled reverse AGC amplifier 1, and second input of voltage-controlled reverse AGC amplifier 1 links to each other the output connection mixer of voltage-controlled reverse AGC amplifier with peak value holding unit except that this input channel input channel of road.Wherein, the input channel connected mode corresponding with the corresponding input channel of MIC2 and MIC3 and MIC1 is the same, at this present embodiment this is repeated no more.
In the present embodiment; After the signal of this passage carries out the amplitude voltage transformation, utilize the negative sense agc circuit, thereby produce masking effect the inhibition that gains of other passage; Strong signalling channel will force gain to suppress to other passage, the noise of other passage input that is used to decay.Wherein, this partial function of gain controller can be configured and remove through dsp processor, also can directly use the controller of wireless communication section to control.
Wherein, receive words, import wireless communication module audio input interface partly again after the signal that returns through the signal after the mixer addition and echo canceler circuit subtracts each other and carry out digitized processing in order to balance out this locality that Mike receives.Wherein, the signal that echo canceler circuit need be offset is the signal that microphone receives from loud speaker, and the loud speaker transfer voice of each microphone relatively exists different attenuation ratios and phase difference.In the present embodiment, echo canceler circuit can use the DSP digital audio signal processor to carry out offsetting after the self adaptation computing, also can adopt fairly simple phase shift subtracter to carry out echo cancelltion and handle, and also can obtain reasonable effect.
Referring to Fig. 2, alternatively, in the present embodiment, the output of echo canceler circuit can connect second input of gain controller simultaneously.Concrete, the signal of exporting from echo canceler circuit can also export gain controller to, and the signal of exporting with gain controller carries out subtraction, to balance out this locality receipts words that Mike receives.Referring to Fig. 3, the signal part that echo canceler circuit is returned inputs to voltage-controlled reverse AGC amplifier, carries out signal cancellation, and another part inputs to input amplifier and carries out signal cancellation.In the present embodiment, the signal of exporting from echo canceler circuit exports gain controller and mixer simultaneously to, can reach better noise reduction.
The beneficial effect that the utility model technical scheme is brought is: use a kind of system of multichannel microphone to come that the matching and fixing platform is realized in many ways, many people conversation.Use multichannel microphone automatic gain control mutual exclusion simultaneously; When one side speaks; The sound of its other party can be suppressed the decay certain proportion, and rejection ratio can be regulated, perhaps can quiet other passage through hand switch; The principle of coming realization body preferentially to send words, shelter noise, improve phone hands-free send the words effect.
Embodiment 3
Referring to Fig. 4, present embodiment provides a kind of terminal, comprises the handfree circuit that embodiment 1 provides, and this handfree circuit comprises at least two Mikes, gain controller, mixer, echo canceler circuit, radio communication communication audio signaling interface;
Wherein, Gain controller comprises the input multiplexer corresponding with each Mike; The input of the input channel corresponding with Mike links to each other in each Mike and the gain controller, and the output of gain controller links to each other with the first input end of mixer, and the output of mixer links to each other with the input of radio communication audio signal interface; The output of radio communication audio signal interface connects the input of echo canceler circuit, and the output of echo canceler circuit connects second input of mixer.
Alternatively, in the present embodiment, handfree circuit also comprises: the hand switch corresponding respectively with Mike; Wherein, Mike is connected with gain controller through hand switch or breaks off.
Further, in the present embodiment, the every road input channel in the gain controller comprises: input amplifier, amplitude voltage transformation module, peak value keep delay unit, voltage-controlled reverse AGC amplifier; Wherein, First output of input amplifier links to each other with an end of amplitude voltage transformation module; The other end of amplitude voltage transformation module keeps an end of delay unit to link to each other with peak value; The other end of peak value maintenance delay unit links to each other with an end of the AGC amplifier of the input channel except that input channel; Second output of input amplifier links to each other with the first input end of voltage-controlled reverse AGC amplifier, and second input of voltage-controlled reverse AGC amplifier links to each other with the peak value holding unit of the input channel except that input channel, and the output of voltage-controlled reverse AGC amplifier connects mixer.
Alternatively, in the present embodiment, the output of echo canceler circuit connects second input of gain controller simultaneously.
Further, in the present embodiment, echo canceler circuit comprises: DSP digital audio signal processor or phase shift subtracter.
The beneficial effect that the utility model technical scheme is brought is: adopt the input of loquacity tube; Improve and send words signal to noise ratio and definition; Be applicable to the scene of multi-user shared wireless telephone call; Built-in expansion gain controlling of radio telephone and echo inhibit feature are realized inhibition of radio telephone Handless system echo and the high communication effect of signal to noise ratio simultaneously, can satisfy the demand that different user while or timesharing insert.
The above is merely the preferred embodiment of the utility model, and is in order to restriction the utility model, not all within the spirit and principle of the utility model, any modification of being done, is equal to replacement, improvement etc., all should be included within the protection range of the utility model.