CN1062697C - Chip for detecting telephone signals with digital signal processor and performing digital communication - Google Patents
Chip for detecting telephone signals with digital signal processor and performing digital communication Download PDFInfo
- Publication number
- CN1062697C CN1062697C CN96111377A CN96111377A CN1062697C CN 1062697 C CN1062697 C CN 1062697C CN 96111377 A CN96111377 A CN 96111377A CN 96111377 A CN96111377 A CN 96111377A CN 1062697 C CN1062697 C CN 1062697C
- Authority
- CN
- China
- Prior art keywords
- signal
- digital signal
- signal processor
- chip
- frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The present invention relates to a chip for detecting various telephone signals and carrying out data communication by a digital signal processor (DSP), which can not only be widely applied to a telephone and a fax machine so as to detect various signals of a telephone network, but also be used for carrying out the point-to-point data communication. The hardware architecture of the chip mainly comprises an anti-noise filter, an A/D convertor, the DSP, a data input memory, a signal output encoder, an ROM (32K<*>16), an RAM (32K<*>16) and other units. The chip can easily expand the kinds of identification signals under the condition of no need of any expansion.
Description
The chip that the present invention detects various telephone signals and carries out data communication for a kind of use digital signal processor (DSP).
Press, the device that carries out the telephone signal detection at present in the telephone set all is that nationality is realized by wave filter technology, the defective of this kind technology is all need design a special filter for each frequency, so its design and cost of manufacture on hardware device is quite high, even utilize digital signal processor or utilize software simulation, its program is also rather complicated, is difficult to expand, and the demand that also can't meet in the ordinary course of things, data communication.
The objective of the invention is to solve the defective that the device that carries out the telephone signal detection in the conventional telephone set is difficult to expand and can't satisfy data communication technically, the assembly type chip that is provided is provided, need not carry out under the situation of any expansion, just can expand the kind of identification signal easily.
Fig. 1 is a hardware structure schematic diagram of the present invention;
Fig. 2 is the stopband/pass band damping characteristic schematic diagram of anti-clutter filter of the present invention;
Fig. 3 is the logic block schematic diagram of digital signal processor of the present invention (DSP);
Fig. 4 is the hardware structure schematic diagram of one embodiment of the invention;
Fig. 5 is the logic block schematic diagram of the digital signal processor (DSP) of one embodiment of the invention.
Hardware structure of the present invention is consulted shown in Figure 1ly, mainly is by anti-clutter wave filter 1, analog-to-digital conversion Device (A/D) 2, digital signal processor (DSP) 3, data input store 4, signal output coder 5 with Reach seven parts such as read-only storage (ROM) 6 and random access memory (RAM) 7 and form, wherein should be anti-assorted Wave filter 1 is connected with digital signal processor (DSP) 3 via analog-digital converter (A/D) 2, other Data input store 4, signal output coder 5, read-only storage (ROM) 6 and random access memory (RAM) 7 are connected with this digital signal processor (DSP) 3 respectively.
Anti-clutter filter 1 of the present invention mainly before carrying out analog-to-digital conversion, will be lower than the frequency filtering of half sampling frequency.Because, the typical bands at phone networking is 300-700Hz, and the generally the highest 300Hz that is no more than of the signal on the phone networking, so, the sampling frequency that this wafer uses is decided to be 6400Hz, this promptly requires the above signal of anti-clutter filter elimination 3200Hz, the characteristic of anti-clutter filter as shown in Figure 2, its stopband should be than pass band damping at least more than the 40DB.If the analog to digital converter 2 that is adopted has the function of anti-clutter, then this partial circuit can omit.
Analog to digital converter of the present invention (A/D) the 2nd is a digital signal with analog signal conversion, and this is to carry out signal processing because of the core of chip of the present invention system uses digital method.So, must be the digital signal that digital signal processor can be discerned with analog signal conversion by analog to digital converter 2.In addition, because the signal amplitude on the telephone wire has very big dynamic range, often more than 40db, the conversion range of its analog to digital converter also should be greater than 40db, so the quantification (Quantitative) after its conversion should be worked energetically 14bit than coefficient.
Digital signal processor of the present invention (DSP) 3 is the core of this chip, meaning is that whole signal processing and other necessary digital processings all carried out via this digital signal processor 3, when the running beginning, earlier the instruction code in the read-only memory 6 is written in the high-speed random access memory 7, and then carries out necessary digital processing by digital signal processor 3.
Data of the present invention input holder 4 be with input data storing in holder, determining the kind of measured signal, 5 of signal output coders be will signal through the output of coding back, read-only memory 6 is employing 32K
*16 read-only memory, random access memory 7 then are to adopt 32K
*16 high-speed random access memory.
Consult shown in Figure 3, Fig. 3 is the logic calcspar of this digital signal processor (DSP) 3, at first, when data input cell 8 coefficient word signal processors (DSP) 3 are accepted from the digital signal of analog to digital converter (A/D) 2, according to the size of data in the nearest 10ms, maximizing is as normalization (Normalize) constant, and after data being done the amplification of correspondence, being sent to leaf transformation (DFT) unit 9 in discrete the winning.
The main feature that this discrete Fourier transform (DFT) unit 9 is different from other telephone signal detector is, can be by the discrete Fourier transform by signal calculated, to understand the distribution situation of signal on whole frequency domain.Because this unary system is to the analysis of whole frequency band, so, can expand easily, and not need extra cost.The computational methods of this discrete Fourier transform (DFT) unit 9 are to use 256 point quick Fourier conversion (FFT).Because chip of the present invention can adopt the sampling rate of 6400Hz, therefore, calculating resulting frequency domain precision via 256 point quick Fourier conversion (FFT) is 6400/256=25Hz.In addition, when calculating discrete Fourier transform (DFT), if counting of calculating is many more, the precision (frequency resolution) of the frequency domain parameter that then obtains is higher, but amount of calculation also is the index raising simultaneously, and computing time is also just long, and the frequency distribution of its gained is long mean value, time precision is low more, and the time precision of the signal of telephone wire often must be more than 10ms.So, if the present invention complies with the computational speed of the digital signal processor that is adopted, the time precision of chip is set in 10ms, the calculating of discrete Fourier transform (DFT) counted be limited in 256 points, then under the sampling rate of 6400Hz, its frequency accuracy (frequency resolution) is 6400/ 256=25Hz.
Wait through aforementioned discrete Fourier transform (DFT) calculating after, can obtain complete frequency distribution situation, via detecting unit 10, the energy size of the frequency that observation post need detect, can determine whether this frequency exists, be provided with a threshold value (Threshold) in this unit, if the energy of frequency is higher than this threshold value, can think that then this frequency exists, otherwise, think that then this frequency does not exist, this threshold value takes to be a key factor that detects really as, and this threshold value must be determined via testing.In addition and since the signal on the phone networking often be double-tone frequently, so when detecting, need to consider two frequencies that all exist as two frequencies, then this signal exists, and does not exist if any a frequency, then this signal does not exist.
This detecting unit 10 and during with a batch total unit 11 be connected, carrying out time counting at signal, institute of time response system some (or a plurality of) frequency that shows of telephone signal exists and the time span of disappearance.According to aforementioned calculate via discrete Fourier transform (DFT) after, be distributed in the signal output on the frequency domain, if (or a plurality of) frequency exists, then this signal exists in 10ms, increase by 1 unit with the existing timing unit of signal this moment, otherwise, the non-existent timing unit of signal is increased by 1 unit.If chip of the present invention is to adopt every 10ms according to discrete Fourier transform (DFT) mode to calculate once, then the time precision that whether exists of signal is 10ms.
These timing units 11 are connected with matching unit 12 respectively again, mate with signal and the standard signal model that will be transmitted.Signals all on the telephone network all need meet specific national standard, so carry out the output of time counting by 11 pairs of signals of aforementioned timing unit, the distribution situation of resultant signal on time-domain, can mate with the national standard model through this this matching unit 12, result system as coupling drops within the allowed band, think that then a certain telephone signal is detected, otherwise, this signal not then.
Then, these matching units 12 are connected with comprehensive unit 13 again, make the output of comprehensive unit 13 comprehensive each road signal.So, wafer of the present invention can not only detect the signal of existence, and can be according to comprehensive each road signal judgment result, detect these signals and when finish, this comprehensive unit 13 is also exported the code (comprising end code) of detected coherent signal, and these codes can be defined voluntarily by the user, any one road signal is detected or finishes, the capital makes this comprehensive unit 13 output correlative codes, if this signal ended then can cause this unit 13 end of output codes.
This comprehensive unit 13 also is connected with signal output coder 5, by this signal output coder 5 signal that is detected is exported.
Data input cell 8 of the present invention again is connected with a zero-crossing rate computing unit 14, in addition with the zero-crossing rate of signal calculated.The characteristics of a sinusoidal signal, tie up to the interior zero passage of one-period twice, by calculating the zero-crossing rate N of a sinusoidal signal, just can obtain its frequency F=N/2 easily, this kind computational methods are used in the data communication, and frequency shift keying (frequency-shift keying is called for short FSK) data are made up of the sinusoidal signal of two frequencies, low frequency representative " 1 ", high frequency representative " 0 ".But first constantly, only may have the sinusoidal signal of a frequency, by simply by calculating zero-crossing rate, can be separately with two frequency zones, thus reach the purpose of differentiation " 0 " and " 1 ".
This zero-crossing rate computing unit 14 is connected with time counting unit 15, because the characteristics of fsk data are that the time that each sinusoidal signal exists is the integral multiple of certain minimum value.If the fsk signal of chip detection 1200dPS of the present invention, the minimum time 1/1200=833 μ s that exists of each signal then, again by the result of zero-crossing rate respectively to two frequency computation part, then can obtain their distribution situations on time-domain, if time precision of the present invention is the time interval 1/6400=156 μ s of sample rate, then each band frequency will be made up of a string continuous " 0 " or " 1 ", and " 0 " that each section is continuous or the number of " 1 " have 833/156＞=5 at least.
At last, this time counting unit 15 is connected with a logic determines part 16 again, when making the present invention detect the fsk signal of 1200dbs, according to 1200Hz presentation logic " 1 ", 2400Hz presentation logic " 0 " by calculating two distributions of frequency on time-domain, converts thereof into logical zero and logical one, and initial from fsk signal, every interval 1/1200=833 μ s extracts the logical value of a logical value as this section.Press, the present invention is in order to the form of 1200bPS fsk signal system employing a start bit, 8 data bit and a position of rest of communication, the standard of symbol CCITT.But, the form that the user also can own definition of data.
Now careful just the present invention one of is applied in the telephone set embodiment, consults shown in the Figure 4 and 5, is described in detail as follows:
Be provided with the analog to digital converter 102 of tool anti-clutter function among this embodiment, this modulus adopts the oval low pass filter in 8 rank according to being provided with the anti-clutter filter in the transducer 102, and its stopband goes out common decay 40db at least.
Digital signal processor among this embodiment (DSP) 103, its clock frequency is 40MHz, all signal processing and other necessary processing are all finished via this processor 103, data input store 104 stores the input data, in the kind of determining measured signal, signal output coder 105 is with behind the signal process coding, and detected signal is exported, and its read-only memory (ROM) 106 adopts 32K
*16 read-only memory, 107 of its random-access memory (ram)s adopt 32K
*16 high-speed random access memory.During the running beginning, earlier the instruction code in the read-only memory (ROM) 106 is written in the high-speed random access memory (RAM) 107, and then, carries out necessary digital processing by this digital signal processor (DSP) 103.
The data input cell 108 of digital signal processor among this embodiment (DSP) 103 is after accepting the digital signal that transmits from analog to digital converter, size according to data in the nearest 10ms, find out its maximum, as normaliztion constant, and data are done corresponding amplification, be sent to discrete Fourier transform (DFT) unit 109.
This discrete Fourier transform (DFT) unit 109 adopts the computational methods of fast Fourier transform (FFT).Because the computing genealogy of law of fast Fourier transform is carried out at plural number, and actual signal is real signal, and promptly its imaginary part is 0.So, can be by calculating 128 point quick Fourier conversion, obtain then 256 discrete rich in the value of leaf transformation, so, can save the time about half approximately, simultaneously, save the memory space of half, and 256 real input signal formed one group of 128 complex signal, and its real part is the real signal of even number point, its imaginary part is the real signal of odd point:
That is: (U) i=X (1i)=jX (2i+1) i=0,1 ..., 127
The discrete Fourier transform of calculating U (i) can obtain Ur (k), Ui (k), and k=0,1 ..., 127
Calculate U (k)=1/2[Ur (k)+Ur (128-k)]+1/2j[Ui (K)-Ui (128-k)]
W(k)=1/2[Ui(k)+Ui(128-k)]-1/2j[Ur(k)-Ur(128-k)]-2πj/(2N)K
X(k)=V(k)+W(k).e?K=0，1，…，127
X (k) is the discrete fourier cross-over value of input real signal X (t), because X (k) is a symmetry, so, in fact only need front or back promptly enough at 128.
After present embodiment calculates discrete Fourier transform, can obtain complete frequency distribution situation, via detecting unit 110, the frequency that observation post is concerned about is 350Hz+440Hz, 400Hz, 450Hz, 900Hz, 1400Hz, 1800Hz, 2130Hz+2750Hz, 440Hz+480Hz, 480Hz+620Hz, calculate 350 respectively, 400,440,450,480,620,900,1400,1800,2130, the energy of 2750Hz, it is compared with threshold value separately, if it is bigger, represent that then this frequency exists, if it is less, represent that then this frequency does not exist, if 350Hz and 440Hz, 440 and 480Hz, 480Hz and 620Hz, 2130Hz and 2750Hz exist simultaneously, then represent 350Hz+440Hz, 440Hz+480Hz, 480Hz+620Hz, four pairs of signals such as 2130Hz+2750Hz exist respectively, otherwise, then do not exist, the threshold value of each frequency needs to determine via experiment.
Timing unit 11 is to carry out time counting at signal among this embodiment, a unit representation 10ms, and signal exists and represents that with ON signal does not exist with OFF and represents.If there be (ON) in signal, represent that then signal exists in this 10ms, the calculated value of ON is increased by 1 unit, i.e. 10ms, otherwise representing does not have this signal in this 10ms increases by 1 unit, i.e. 10ms with the calculated value of OFF.The one group of representation signal that so, promptly forms ON-OFF has or does not have numerical value how long fully.
These timing units 111 are connected with matching unit 112 respectively again, mate with signal and the standard signal model that will be transmitted, and press, and the signal that can detect among this embodiment has:
The national standard signal of Britain
The national standard signal of the U.S.
At first, relatively whether measured signal is consistent with the frequency of master pattern, if inconsistent, then be judged to be the signal of non-this class standard, compare, if consistent with other model, then relatively the ON-OFF characteristic value of this signal whether with conformance to standard, if consistent, then be judged to be such signal.Otherwise, compare with other model.
These matching units 112 are connected with comprehensive unit 113 again, make the output of comprehensive unit 113 comprehensive each road signal.So, present embodiment can not only detect the signal of existence, and can be according to comprehensive each road signal judgment result, when detect these signals finishes, this comprehensive unit 113 is also exported the code (comprising end code) of detected coherent signal, and these codes can be defined voluntarily by the user, and any one road signal is detected or finishes, the capital makes this comprehensive unit 113 correlative code immediately, and its code is;
The national standard signal code of Britain
The national standard signal code of the U.S.
The data input cell 108 of present embodiment again, be connected with a zero-crossing rate computing unit 114 in addition, zero-crossing rate with signal calculated, press, the characteristics of a sinusoidal signal, tie up to the interior zero passage of one-period twice, by calculating the zero-crossing rate N of a sinusoidal signal, just can obtain its frequency FZN/2 easily, this kind computational methods are used in the data communication, and frequency shift keying (frequency-shift keying is called for short FSK) data are made up of the sinusoidal signal of two frequencies, 1200Hz represents " 1 ", and 2400Hz represents " 0 ".But each is constantly, only may have the sinusoidal signal of a frequency, by calculating zero-crossing rate simply, can be separately with two frequency zones, thus reach the purpose of differentiation " 0 " and " 1 ".
This zero-crossing rate computing unit 114 is connected with time counting unit 115, because, the characteristics of fsk data are that the time that each sinusoidal signal exists is the integral multiple of certain minimum value, if the fsk signal of the chip detection 1200dps of present embodiment, then the minimum time of each signal existence is 1/1200=833US, again by the result of zero-crossing rate respectively to two frequency countings, then can obtain their distribution situations on time-domain, if time precision of the present invention is the time interval 1/6400=156SS of sample rate, then each band frequency will be made up of a string continuous " 0 " or " 1 ", and each section number of it " " or " 1 " continuously has 833/156＞25 at least.
At last, when logic judgment unit 116 detects the fsk signal of 1200dbs in this example, according to 1200Hz presentation logic " 1 ", 2400Hz presentation logic " 0 ", by calculating two distributions of frequency on time-domain, convert thereof into logical zero and logical one, and initial from fsk signal, every interval 1/1200=833SS extracts the logical value of a logical value as this section.Press, the present invention adopts the form of a start bit, 8 data bit and a position of rest in order to the 1200bPSFSK signal of communication, meets the standard of CCITT, but, the form that the user also can own definition of data.
In addition, the above only is one of the present invention preferred embodiment, is familiar with the personage of this skill generally, and the various variations that utilize spirit of the present invention to make must be contained within the present invention.
Claims (15)
1. chip that uses digital signal processor to detect various telephone signals and carry out data communication is characterized in that this chip comprises:
One analog to digital converter is the digital signal that this digital signal processor can be discerned with analog signal conversion, and this analog to digital converter has the function of anti-clutter;
One digital signal processor is connected with analog to digital converter, handles at whole signals and data;
One data input holder links to each other with digital signal processor, will import data storing in this holder, to determine the kind of measured signal;
One signal output coder links to each other with digital signal processor, and signal is exported through the coding back;
One random access memory links to each other with digital signal processor, adopts high-speed random access memory.
2. chip that uses digital signal processor to detect various telephone signals and carry out data communication is characterized in that this chip comprises:
One anti-clutter filter is connected with digital signal processor via analog to digital converter, before carrying out analog-to-digital conversion, will be lower than the frequency filtering of half sampling frequency;
One analog to digital converter is the digital signal that this digital signal processor can be discerned with analog signal conversion;
One digital signal processor is connected with analog to digital converter, handles at whole signals and data;
One data input holder links to each other with digital signal processor, will import data storing in this holder, to determine the kind of measured signal;
One signal output coder links to each other with digital signal processor, and signal is exported through the coding back;
One random access memory links to each other with digital signal processor, adopts high-speed random access memory.
3. the chip that use digital signal processor as claimed in claim 1 detects various telephone signals and carries out data communication, it is characterized in that, the sampling frequency that this chip uses can be set at 6400Hz, promptly require the anti-above signal of clutter function elimination 3200Hz of wanting of described analog to digital converter, its stopband is than decaying at least more than the 40DB usually.
4. the chip that use digital signal processor as claimed in claim 2 detects various telephone signals and carries out data communication, it is characterized in that, the sampling frequency that this chip uses can be set at 6400Hz, promptly require the above signal of anti-clutter filter elimination 3200Hz, its stopband is than decaying at least more than the 40DB usually.
5. the chip that use digital signal processor as claimed in claim 1 or 2 detects various telephone signals and carries out data communication is characterized in that the conversion range of this analog to digital converter is greater than 40db.
6. the chip that use digital signal processor as claimed in claim 1 or 2 detects various telephone signals and carries out data communication is characterized in that, this digital signal processor also comprises:
One data input cell, when tying up to reception from the digital signal of analog to digital converter output, according to the size of data in the nearest 10ms, maximizing as normaliztion constant, and is done corresponding amplification with data;
One discrete Fourier transform unit receives the signal by data input cell output, by by leaf transformation in discrete the winning of signal calculated, understands the distribution situation of signal on whole frequency domain;
One detecting unit, in order to detect the complete frequency distribution situation of gained after this direct computation of DFT transformation calculations, the energy size of the frequency that observation post need detect is to determine whether this frequency exists;
Unit during one batch total is connected with this detecting unit, to carry out time counting at signal;
One group of matching unit is connected with this timing unit respectively respectively, mates with signal and the standard No. model that will be received, and drops within the range of tolerable variance as the result system of coupling, thinks that then a certain telephone signal is detected, otherwise, then think not this signal;
One comprehensive unit, be connected with this group matching unit, the output of comprehensive each road signal, can not only detect the signal of existence, and can detect these signals and when finish, and export the code of detected coherent signal according to comprehensive each road signal judgment result, this comprehensive unit also is connected with this signal output coder, by this signal output coder the signal that is detected is exported.
7. the chip that use digital signal processor as claimed in claim 6 detects various telephone signals and carries out data communication is characterized in that, the computational methods of this discrete Fourier transform unit can be used 256 point quick Fourier conversion.
8. the chip that use digital signal processor as claimed in claim 6 detects various telephone signals and carries out data communication, it is characterized in that, be provided with a threshold value in this detecting unit, energy as frequency is higher than this threshold value, can think that then this frequency exists, otherwise, think that then this frequency does not exist.
9. the chip that use digital signal processor as claimed in claim 8 detects various telephone signals and carries out data communication, it is characterized in that, this threshold value must be determined via experiment, and when detecting, need to consider two frequencies that all exist as two frequencies, then this signal exists, do not exist if any a frequency, then this signal does not exist.
10. the chip that use digital signal processor as claimed in claim 6 detects various telephone signals and carries out data communication, it is characterized in that, after discrete Fourier transform calculating, be distributed in the signal output on the frequency domain, if one or more frequencies exist, then this signal existed in the unit interval, and increase by 1 unit with the existing timing unit of signal this moment, otherwise the timing unit that signal is not existed increases by 1 unit.
11. the chip that use digital signal processor as claimed in claim 10 detects various telephone signals and carries out data communication is characterized in that, this unit interval can be 10ms.
12. the chip that use digital signal processor as claimed in claim 8 detects various telephone signals and carries out data communication is characterized in that these codes can be defined voluntarily by the user.
13. the chip that use digital signal processor as claimed in claim 6 detects various telephone signals and carries out data communication, it is characterized in that, this data input cell is connected with a zero-crossing rate computing unit in addition, zero-crossing rate with signal calculated, make separately, reach the purpose of differentiation " 0 " or " 1 " two frequency zones.
14. the chip that use digital signal processor as claimed in claim 13 detects various telephone signals and carries out data communication, it is characterized in that the zero-crossing rate computing unit is connected with a time counting unit, make result by zero-crossing rate respectively to two frequency countings, to obtain their distribution situations on time-domain.
15. the chip that use digital signal processor as claimed in claim 14 detects various telephone signals and carries out data communication, it is characterized in that, this time counting unit partly is connected with a logic determines, by calculating two distributions of frequency on time-domain, convert thereof into logical zero and logical one.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN96111377A CN1062697C (en) | 1996-09-05 | 1996-09-05 | Chip for detecting telephone signals with digital signal processor and performing digital communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN96111377A CN1062697C (en) | 1996-09-05 | 1996-09-05 | Chip for detecting telephone signals with digital signal processor and performing digital communication |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1147740A CN1147740A (en) | 1997-04-16 |
| CN1062697C true CN1062697C (en) | 2001-02-28 |
Family
ID=5121099
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN96111377A Expired - Fee Related CN1062697C (en) | 1996-09-05 | 1996-09-05 | Chip for detecting telephone signals with digital signal processor and performing digital communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1062697C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102201872A (en) * | 2010-03-22 | 2011-09-28 | 吴佳欣 | Low-power-consumption underwater acoustic communication arousing equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2080269U (en) * | 1989-09-30 | 1991-07-03 | 湖南省零陵地区专利实验工厂 | Compactible detect double voice multi-frequency/pulse telephone set |
| CA2118552A1 (en) * | 1993-03-23 | 1994-09-24 | Edward M. Roney, Iv | Discrete audio frequency tone detection |
| US5563942A (en) * | 1994-02-21 | 1996-10-08 | Mitel Corporation | Digital call progress tone detection method with programmable digital call progress tone detector |
-
1996
- 1996-09-05 CN CN96111377A patent/CN1062697C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2080269U (en) * | 1989-09-30 | 1991-07-03 | 湖南省零陵地区专利实验工厂 | Compactible detect double voice multi-frequency/pulse telephone set |
| CA2118552A1 (en) * | 1993-03-23 | 1994-09-24 | Edward M. Roney, Iv | Discrete audio frequency tone detection |
| US5563942A (en) * | 1994-02-21 | 1996-10-08 | Mitel Corporation | Digital call progress tone detection method with programmable digital call progress tone detector |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1147740A (en) | 1997-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4932062A (en) | Method and apparatus for frequency analysis of telephone signals | |
| CN1121681C (en) | Speech processing | |
| Tucker | Voice activity detection using a periodicity measure | |
| US5319703A (en) | Apparatus and method for identifying speech and call-progression signals | |
| EP0153787B1 (en) | System of analyzing human speech | |
| US4827519A (en) | Voice recognition system using voice power patterns | |
| CN1064771C (en) | Discriminating between stationary and non-stationary signals | |
| CN101847412B (en) | Method and device for classifying audio signals | |
| CN1013525B (en) | Real-time phonetic recognition method and device with or without function of identifying a person | |
| JPH0624398B2 (en) | Tone detection method | |
| JPS59100643A (en) | Method and device for discriminating noise level on telephone channel | |
| US7804942B2 (en) | Tone detector judging a detection of a predetermined tone signal by comparing a characteristic quantity of the tone signal with characteristic quantities of other signals | |
| US5239574A (en) | Methods and apparatus for detecting voice information in telephone-type signals | |
| JPH06504662A (en) | Reconfigurable parameterized DTMF detector | |
| US4864307A (en) | Method and device for the automatic recognition of targets from "Doppler" ec | |
| CN1062697C (en) | Chip for detecting telephone signals with digital signal processor and performing digital communication | |
| US4388491A (en) | Speech pitch period extraction apparatus | |
| KR0149759B1 (en) | Dtmf detector using dsp chip | |
| CA2112767C (en) | Tone-detecting method for detecting at least one tone in a dual-tone multifrequency signal, call-progress method using the same | |
| CN1218945A (en) | Identification of static and non-static signals | |
| US5251256A (en) | Independent hysteresis apparatus for tone detection | |
| US4982433A (en) | Speech analysis method | |
| JPS58123293A (en) | Multifrequency signal detecting method | |
| KR960002389B1 (en) | Detecting device and method of fast significant sample | |
| EP0283743B1 (en) | Pattern recognition apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20010228 Termination date: 20100905 |