Dual-tone Multifrequency Research Articles

Dtmf Detection Using Goertzel Algorithm

Abstract: Dual-tone multi-frequency(DTMF) is an international signaling standard for telephone digits(number buttons). These signals are used in touch-tone telephones as well as many other areas. Since analog devices are rapidly changing with digital devices, digital DTMF decoders become more important. The subject of this paper is to build a dual-tone multi-frequency(DTMF) signal detector. There are many algorithms for DTMF detection, and among all of them the chosen one is Goertzel’s algorithm. It is one of the simplest algorithms of all and it is very often used in practical realizations. The simulation of this algorithm is done in MATLAB and outputs of this test are given in this paper.

A New Algorithm for Tone Detection

This study presents a new algorithm for detecting dual-tone multi-frequency (DTMF) signals. The discrete multi-frequency transform (DMFT) method with optimal phase was employed to reduce the DTMF detection computations. With the DMFT approach, the pass-band ripple is employed as a cost function, and the optimal phase can be obtained using the open-loop search method. Compared to the traditional discrete Fourier transform (DFT) approach, not only is a computational saving of 75% to 83% achieved, but spectrum efficiency is also maintained. These experimental results demonstrate the excellent performance of the DMFT method.

GSM based Wireless Sensor Network to Measure Global Warming, Humidity and CO2

This paper discusses GSM based global wireless sensor network to measure increase of global warming & air pollution. Each motes of the wireless sensor network can cover the area wherever GSM network is available. Each mote consists of temperature, humidity & co2 measuring sensors, equipped with low power consuming GSM module, data logging facility & real time stamp. Motes can communicate with each other but most of the time they communicate with the central receiver. Central receiver is capable of receiving calls from modes, display the data in portable TFT LCD screen & also transmit data to computer through USB. To transmit data sensors generate call to receive station. To receive data receiver first verify the caller ID and then it receives the call. Sensors send or receive data through Dual tone multi frequency (DTMF) and will receive commands through DTMF also. Lots of control system has been designed using DTMF but in this project DTMF tones are used to create all characters of an ASCII table. The number of motes can be connected are unlimited and the coverage area is also unlimited in this project. General Terms Wireless Sensor Network, GSM, DTMF, Sensors.

Low-Cost Teleoperation of Remotely Located Actuators Based on Dual Tone Multi-Frequency Data Transfer

DTMF (Dual Tone Multi Frequency) is a system of signal tones used for telecommunications. DTMF uses two tones to represent each key on the touch pad. DTMF data transfer technique has advantages such as high reliability, constant speed, and high signal to noise ratio, low cost and optimal utilization of existing resources. These features make DTMF an attractive Data Transfer Technique. It finds application in home and car security systems, robot control, SMS and voice call controlled industrial applications. In this paper, we discuss the use of DTMF data transfer in a voice call to control a toy car. Cell phone 1(CP 1), which is at user end, makes a call to cell phone 2(CP 2) at the machine end and establishes a connection. A key is pressed at the user side. Two tones corresponding to one key are encoded and sent through the cell phone network. Both tones are tapped through the earphone jack of cell phone at machine end and are decoded. The output is fed to a Micro-controller. The Micro-controller is connected to the remote control unit of the toy car, which in turn controls the motion of the car. The car moves in various directions according to the key pressed user. The electronic circuit is divided into 2 parts. The transmitter side consisting of Cell phone 1 with an inbuilt encoder and the receiver side consisting of Cell Phone 2, 8870 DTMF decoder and Atmega 16 micro-controller. The programming has been carried out on AVR Bascom®.

Pitch perception and frequency-following response in inharmonic signals.

It has been suggested that auditory-evoked frequency-following response (FFR) is related to pitch [Greenberg et al., Hear. Res. 25, 91–114 (1987)], which is usually related to fundamental frequency of complex sounds. We examined FFR to dual-tone multi-frequency (DTMF) signals used in telephone communication. As these tones have been used to produce melodies, it was expected that they would have a measurable pitch and this was also determined in a behavioral task. Twelve subjects matched perceived pitch of DTMF signals to a pure tone via method of adjustment. In addition, the FFR to the same signals was recorded from the same subjects to establish whether significant FFR energy was present at the frequency of the perceived pitch. Correlation analysis of data from the behavioral task showed wide variation among subjects, with many identifying the perceived pitch as matching the lower of the two partials. Significant FFR energy was detected at both partials, which does not clarify the relationship between perceived pitch and the evoked response. In addition, we show that perceived pitch is highly context dependent and present data from FFR to stimuli in melodic contexts.

Low Computational Complexity, Low Power, and Low Area Design for the Implementation of Recursive DFT and IDFT Algorithms

A novel recursive algorithm for discrete Fourier transform (DFT) and its inverse transform (IDFT) is proposed in this brief. It was found that the proposed algorithm and its implementation outperformed other existing recursive algorithms. The proposed algorithm was found to 1) reduce multiplication computations by 50.5% using the symmetric identity of coefficients and a resource-sharing technique and register-splitting scheme; 2) decrease read-only memory sizes by 50% compared with conventional algorithms; 3) reduce the number of multipliers implemented by 80% compared with the latest algorithm; and 4) increase data throughput by 100% per transformation. This design is suitable for communication systems and digital radio mondiale (DRM) systems, such as dual-tone multifrequency detection and coded orthogonal frequency-division-multiplexing modulation. The algorithm was designed and fabricated using a 0.18 ?m 1P6M complementary metal-oxide-semiconductor process. The core area is 397 × 388 ?m2, including the DFT and IDFT modules. For modern applications (voice over packet and DRM), this processor only consumes 2.96 mW at 25 MHz. Furthermore, it can calculate the 212/165/106/288/256/176/112-point DFTs and IDFTs.

Application on call signal system and call control of HMP

The communication signal system and signal control of Host Media Processing(HMP) were studied.One new model of communication using HMP,which combined SIP and MS RCT as communication protocols,was proposed.The procedure of improving the identification of Dual Tone Multi Frequency(DTMF) under this model was provided,and the methods of reducing the transportation time of signal were informed.

System and method for voice based network management

The present invention provides a system and method for voice based network management. A network management system uses voice based scripts that allow network management operations to be performed over a phone. In one embodiment, the voice based scripts use a Voice Extensible Markup Language (VXML). However, the voice based script can be any form of communication that allows a user to conduct network management operations using Dual Tone Multi-Frequency (DTMF) signaling or speech commands.

Carrier Class High Density VoIP Media Gateway using Hardware Software Distributed Architecture

This paper presents a system on chip (SOC) based high-density carrier class Voice over Internet Protocol (VoIP) media gateway. The design exploits three levels of parallelism namely HW/SWpartitioning, multiprocessing and instruction level parallelism. The system facilities the carrier class service providers to transform channels on PSTN network to IP network, enabling the consumers to enjoy several value added services, such as voice, data, fax and video all through a uniform network at lower cost. The SoC implements a high-density media gateway switch for carrier class VoIP applications. The solution is synthesized to operate at 266 MHz handling up to OC-3 data rate port density equivalent to 2016 simultaneous calls on a single chip and it can be cascaded to support OC-12 and OC-48 rate port density on single board in different configurations. On each channel the SoC supports up to 128 ms tail length G.168 compliant Line Echo Cancellation (LEC), voice activity detection (VAD), comfort noise generation (CNG) and discontinuous transmission (DTX), dual tone multi frequency (DTMF) detection and generation, variety of G.xxx voice codecs, V. 17 Fax and V.34 data modem standards and MPEG4 video compression/decompression algorithms. The solution is compared with the existing architectures and commercial products; it offers 3x to 10x cost, size, power and port density performance improvements with IP and PSTN internetworking support. The media gateway system based on the presented architecture has been used to develop IP-based automatic call distribution (ACD) by etel Pvt. Ltd and installed in Telephone Inquiry Exchange of Pakistan Telecom and its variants are being tested by Buraq Telecom for installation in their service network.

VLSI Architecture for the Low-Computation Cycle and Power-Efficient Recursive DFT/IDFT Design

In this paper, we propose one low-computation cycle and power-efficient recursive discrete Fourier transform (DFT)/inverse DFT (IDFT) architecture adopting a hybrid of input strength reduction, the Chebyshev polynomial, and register-splitting schemes. Comparing with the existing recursive DFT/IDFT architectures, the proposed recursive architecture achieves a reduction in computation-cycle by half. Appling this novel low-computation cycle architecture, we could double the throughput rate and the channel density without increasing the operating frequency for the dual tone multi-frequency (DTMF) detector in the high channel density voice over packet (VoP) application. From the chip implementation results, the proposed architecture is capable of processing over 128 channels and each channel consumes 9.77 μW under 1.2 [email protected] in TSMC 0.13 1P8M CMOS process. The proposed VLSI implementation shows the power-efficient advantage by the low-computation cycle architecture.

Efficient Multitone Detection [DSP Tips & Tricks

This article presents the digital signal processing (DSP) tricks employed to build a computationally efficient multitone detection system, implemented without multiplications and with minimal data memory requirements. More specifically, the article describes the detection of incoming dial tones, validity checking to differentiate valid tones from noise signals, and the efficient implementation of the detection system. While the discussion focuses on dual-tone multifrequency (DTMF) telephone dial tone detection, the processing tricks presented may be employed in other multitone detection systems

DIADEM: implementation of a comprehensive disease management programme for type 2 diabetes

The purpose of the study was to evaluate the feasibility and acceptance of an IT-based diabetes disease management programme. The study was performed at two test sites in Aachen (Germany) and Cardiff (UK) including 166 and 137 patients respectively. The study focused on the technical feasibility of a web-based communication platform and its acceptance among medical professionals, the patient acceptance of entering self-measured data via phone and of service-centre support, the acceptance of implementing quality management measures, and the effects of all these measures on glycaemic control. The maximum programme duration was four months at Aachen and six months at Cardiff. The main outcomes were utilisation data, and satisfaction of both patients and physicians with the different components of DIADEM. HbA1c concentrations improved significantly from 7.1±1.0% to 6.8±1.1% in Aachen and from 7.7±1.0% to 7.1±1.1% in Cardiff (each p<0.001). The platform as a hosted ASP (application service provider) solution was accessible using a standard Internet enabled PC. Following training, a fast and efficient introduction of the software to professional users was obtained. Patient acceptance was very high both in terms of utilisation of the system (13 000 data entries performed during 6800 calls) and in terms of patient satisfaction assessed by a patient survey (93% very satisfied or satisfied). Patients strongly preferred a DTMF (dual tone multi-frequency) interface entering data by telephone key-pad rather than voice recognition. This study showed that an IT-based diabetes disease management service improved glycaemic control in patients with type 2 diabetes and could find acceptance by patients and professionals if convenient pathways for data entry and transmission are provided. Copyright © 2005 John Wiley & Sons, Ltd.

Method and apparatus for performing spectral processing in tone detection

A general purpose network tone detection method and apparatus that allows the precise and accurate recognition of North American tones (MF, DTMF (Dual-Tone Multifrequency), and CPT (Call Progress Tones)) and international MF-R2 tones as well as taking into consideration other common tones such as Calling Card Service Prompt and Recall Dial. Through the use of the Discrete Fourier Transform (DFT) on small time windows and by providing phase continuity between these windows, the results of the successive DFTs may be combined and processed by a second DFT computation. This second DFT allows higher frequency resolution without requiring the re-computation of the DFT from the time samples. The resulting effect is a tone receiver with both high time and frequency resolution which consequently leads to robust and accurate tone recognition systems conforming even to the most stringent specification while maintaining low computational requirements.

Processing dual tone multi-frequency signals for use with a natural language understanding system

A method for processing dual tone multi-frequency signals for use with a natural language understanding system can include several steps. The step of determining whether a audio input signal is a dual tone multi-frequency signal or a human speech signal can be included. If the audio input signal is determined to be a dual tone multi-frequency signal, the audio input signal can be converted to at least one text equivalent. Also, the step of providing the at least one text equivalent to a natural language understanding system can be included. The natural language understanding system can determine a meaning from the text equivalent.

Performance of dual tone multi-frequency signal decoding algorithm using the sub-band non-uniform discrete Fourier transform on the ADSP-2192 processor

Efficient decoding of Dual Tone Multi-Frequency (DTMF) signals can be achieved using the sub-band non-uniform discrete Fourier transform (SB-NDFT). In this paper, the details of its implementation on the ADSP-2192 processor are put forward. The decoder performance in terms of its computational complexity and computational speed of this algorithm, implemented on the ADSP-2192 processor, are compared for different implementations of the SB-NDFT algorithm, with and without optimization for the chosen DSP, ADSP-2912. The algorithm is tested for various types of input signals on the DSP and these are compared with the results from Matlab ®. Problems on using other DTMF decoding algorithms that use the conventional discrete Fourier transform (DFT) and the non-uniform discrete Fourier transform (NDFT) are also addressed.

Optimized periodic sigma-delta bitstreams for analog signal generation

This paper describes a new method to generate analog signals with high precision at very low hardware complexity. This method consists in reproducing periodically a portion of the bitstream output of a sigma-delta modulator. This technique utilizes less hardware than conventional analog signal generation methods and does not require a multi-bit DAC. An optimization routine which increases the quality of the signals is presented and signal generation examples are given. The design of a Dual Tone Multi-Frequency generator implemented using an FPGA is also presented.

Efficient dual-tone multifrequency detection using the nonuniform discrete Fourier transform

The International Telecommunication Union (ITU) recommendations for dual-tone multifrequency (DTMF) signaling are not met by conventional DTMF detectors. We present an efficient DTMF detection algorithm based on the nonuniform discrete Fourier transform that meets all of the ITU recommendations. The key innovations are the use of two sliding windows and development of sophisticated timing tests. Our algorithm requires no buffering of input samples. To perform DTMF detection on n telephone channels, our algorithm requires approximately n MIPS on a digital signal processor (DSP), 75+30n words of data memory, and 1000 words of program memory. Using the new algorithm, a single fixed-point DSP can perform ITU-compliant DTMF detection on the 24 telephone channels of a T1 time-division multiple multiplexed telecommunications line.

The FCC's universal service rules (abstract)

The Telecommunications Act of 1996 is considered landmark legislation, especially in the area of universal service. However, the FCC performed even more groundbreaking activity. The FCC was given wide latitude by the Act to interpret the universal service provisions of the Act either narrowly or broadly; the FCC chose the latter. The FCC's interpretation of the Act will have a significant impact on the level of technology implementation and use in American classrooms and libraries. In March 1996, the FCC issued a Notice of Proposed Rulemaking (NPRM) on Universal Service. The NPRM also established a Federal-State Joint Board composed of three FCC Commissioners (the Chairman and two commissioners), four state public service commission representatives nominated by the National Association of Regulatory Utility Commissioners, and one utility consumer advocate nominated by the National Association of State Utility Consumer Advocates. On November 8, 1996, the Joint Board released its Recommended Decision and the FCC adopted its rules based on that recommendation in May 1997. The FCC ruled that all eligible schools and libraties should receive discounts of between 20 and 90 percent (depending on need) on all telecommunications services, Internet access, and internal connections, subject to a $2.25 billion annual cap. In addition, any funds not disbursed in a given year may be carried forward and disbursed in subsequent years without regard to the cap. This provision, according to the FCC, will provide schools and libraries with the maximum flexibility to purchase the services that will meet their communications needs most effectively. In a separate section of the rules, the FCC defined "core services" as: &amp;bull; Voice-grade access to the public switched network, with the ability to place and receive calls &amp;bull; Dual Tone Multifrequency signaling (touch-tone) or its functional equivalent &amp;bull; Single-party service &amp;bull; Access to emergency services &amp;bull; Access to operator services &amp;bull; Access to interexchange services &amp;bull; Access to directory assistance. &amp;bull; Support for toll limitation services (includes both toll blocking and toll control) for low-income consumers. However, as stated in the Act, the FCC was given the latitude to include additional services for schools and libraries. It could have chosen to provide schools and libraries with discounts on (1) only core telecommunications services; (2) core services plus some complement of additional services; or (3) all telecommunications services (including wireless). The FCC adopted the third option, that discounts be provided on all telecommunications services. It stated that this guideline would provide schools and libraries the maximum flexibility to purchase whatever package of telecommunications services they believe would meet their telecommunications service needs most effectively and efficiently. &lt;i&gt;Current Status:&lt;/i&gt; The FCC ruled that it will permit schools to begin using discounted services on January 1, 1998. The presentation will discuss the current status of this legislation.

Artificial neural networks in measurements

This paper, after a brief theoretical background to Artificial Neural Networks (ANNs) reviews their utilization in the field of measurements. The criteria used for choosing between the possible ANN software and hardware implementations are then discussed. The advantages and disadvantages of the possible analogue or digital hardware implementation are also detailed. Some of the applications of ANNs in the measurements field, variously utilizing software, analogue or digital hardware implementations are shown. In particular, the strategies for building suitable ANN-based software models of mixed analogue/digital measurement devices are presented. Successively, a method for designing a neural network able to pre-process signals in an analogue mode is described. Finally, the architecture of a DSP-based neural apparatus for the real-time measurement of the components of a dual-tone multi-frequency signal is given.

Arbitrary multifrequency estimation and the relationship between the LMS and Goertzel algorithms

The relationship between the LMS and the sliding Goertzel (SG) algorithms for Fourier coefficient estimation of sinusoidal components is described given a priori information of the input frequencies. This relationship is established from the point of view that both methods may be considered as narrow bandpass filters tuned to the exact input frequency locations. The LMS algorithm is equivalent to an infinite impulse response (IIR) filter bank which has similar parametrization as the resonator-based filter bank proposed by Padmanabhan and Martin (1987). It is also shown that the SG algorithm provides significant computational savings when compared to the LMS algorithm under the same accuracy and acquisition time conditions. For illustration purposes the problem of dual tone multifrequency (DTMF) estimation and detection is considered.