From MATLAB and Simulink to Real Time with
![From MATLAB® and Simulink® to Real Time with TI DSPs • Frequency Dual Tone From MATLAB® and Simulink® to Real Time with TI DSPs • Frequency Dual Tone](https://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-1.jpg)
From MATLAB® and Simulink® to Real Time with TI DSPs • Frequency Dual Tone Multi • (DTMF) Content developed in partnership with Tel-Aviv University © 2007 Texas Instruments Inc, 0 -1
![DTMF Signals • The DTMF is a popular signaling method between telephones and switching DTMF Signals • The DTMF is a popular signaling method between telephones and switching](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-2.jpg)
DTMF Signals • The DTMF is a popular signaling method between telephones and switching centers • DTMF is also used for signaling between the Telephone network and computer networks • The DTMF signals are Transmitted over a telephone line • Uses speech frequency signals • DTMF signals are the superposition of 2 sine waves with different frequencies © 2007 Texas Instruments Inc, Slide 2
![The DTMF Keypad 1209 Hz 1336 Hz 1477 Hz 697 Hz 1 2 3 The DTMF Keypad 1209 Hz 1336 Hz 1477 Hz 697 Hz 1 2 3](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-3.jpg)
The DTMF Keypad 1209 Hz 1336 Hz 1477 Hz 697 Hz 1 2 3 770 Hz 4 5 6 852 Hz 7 8 9 941 Hz * 0 # © 2007 Texas Instruments Inc, Slide 3
![DTMF Digits © 2007 Texas Instruments Inc, Slide 4 DTMF Digits © 2007 Texas Instruments Inc, Slide 4](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-4.jpg)
DTMF Digits © 2007 Texas Instruments Inc, Slide 4
![DTMF Generation 697 Hz Row Selector 770 Hz 852 Hz Desired Digit 941 Hz DTMF Generation 697 Hz Row Selector 770 Hz 852 Hz Desired Digit 941 Hz](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-5.jpg)
DTMF Generation 697 Hz Row Selector 770 Hz 852 Hz Desired Digit 941 Hz + Dual Tone 1209 Hz Column Selector 1336 Hz 1477 Hz © 2007 Texas Instruments Inc, Slide 5
![DTMF Detection Leading Edge Detection Enable x[n] Frequency Detection Convert to Display © 2007 DTMF Detection Leading Edge Detection Enable x[n] Frequency Detection Convert to Display © 2007](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-6.jpg)
DTMF Detection Leading Edge Detection Enable x[n] Frequency Detection Convert to Display © 2007 Texas Instruments Inc, Slide 6
![Frequency Detection Row Calculation 697 Hz 770 Hz 852 Hz 941 Hz x[n] Digit Frequency Detection Row Calculation 697 Hz 770 Hz 852 Hz 941 Hz x[n] Digit](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-7.jpg)
Frequency Detection Row Calculation 697 Hz 770 Hz 852 Hz 941 Hz x[n] Digit Calculation Calculated Digit Column Calculation 1209 Hz 1336 Hz 1477 Hz © 2007 Texas Instruments Inc, Slide 7
![Simulation (cont. ) Selecting Digits for transmission © 2007 Texas Instruments Inc, Slide 8 Simulation (cont. ) Selecting Digits for transmission © 2007 Texas Instruments Inc, Slide 8](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-8.jpg)
Simulation (cont. ) Selecting Digits for transmission © 2007 Texas Instruments Inc, Slide 8
![Simulation (cont. ) Detected Digits © 2007 Texas Instruments Inc, Slide 9 Simulation (cont. ) Detected Digits © 2007 Texas Instruments Inc, Slide 9](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-9.jpg)
Simulation (cont. ) Detected Digits © 2007 Texas Instruments Inc, Slide 9
![Simulation (cont. ) • The Receiver Performs: sensing Edge Detected Signal Rcv samples Buffer Simulation (cont. ) • The Receiver Performs: sensing Edge Detected Signal Rcv samples Buffer](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-10.jpg)
Simulation (cont. ) • The Receiver Performs: sensing Edge Detected Signal Rcv samples Buffer Digit © 2007 Texas Instruments Inc, New Digit Detect Digit Slide 10
![Simulation (cont. ) • Digit Detection: transforms signal received to digit using the following Simulation (cont. ) • Digit Detection: transforms signal received to digit using the following](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-11.jpg)
Simulation (cont. ) • Digit Detection: transforms signal received to digit using the following detection blocks: X 1 … XN Detect 852 Hz Detect 941 Hz © 2007 Texas Instruments Inc, Detect 1209 Hz X 1 … XN Detect 697 Hz 1 2 3 Detect 770 Hz 4 5 6 Detect 852 Hz 7 8 9 Detect 941 Hz * 0 # Slide 11
![Simulation (cont. ) • Detection block operation: – Input: X 1…XN signal samples – Simulation (cont. ) • Detection block operation: – Input: X 1…XN signal samples –](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-12.jpg)
Simulation (cont. ) • Detection block operation: – Input: X 1…XN signal samples – Output: flag to indicate whether the signal has a correlation with the frequency under detection or not – Implementation: » Band Pass around the frequency under detection » Average the absolute value of the BPF output » Comparing the average to an agreed threshold » Flag is up the average is greater than the threshold Detect fb = X 1…XN © 2007 Texas Instruments Inc, BPF (fb-eps , fb+eps) Threshold Test flag Slide 12
![Real-Time Environment • Based on the Simulation model • R-T Implementation involves detecting the Real-Time Environment • Based on the Simulation model • R-T Implementation involves detecting the](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-13.jpg)
Real-Time Environment • Based on the Simulation model • R-T Implementation involves detecting the digits only • The R-T Simulation involves a few modification to support the interface with the transmitter © 2007 Texas Instruments Inc, Slide 13
![Real-Time Environment (cont. ) PC MATLAB: Ø DTMF transmission Ø GUI PC (Sound Card) Real-Time Environment (cont. ) PC MATLAB: Ø DTMF transmission Ø GUI PC (Sound Card)](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-14.jpg)
Real-Time Environment (cont. ) PC MATLAB: Ø DTMF transmission Ø GUI PC (Sound Card) rtdx Detected Digits DTMF Line In A/D DTMF Receiver TMS 320 C 6713 DSK 6713 © 2007 Texas Instruments Inc, Slide 14
![Real Time Environment (cont. ) • The DTMF signal is processed in order to Real Time Environment (cont. ) • The DTMF signal is processed in order to](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-15.jpg)
Real Time Environment (cont. ) • The DTMF signal is processed in order to overcome DC offset and to make amplitude modifications: © 2007 Texas Instruments Inc, Slide 15
![GUI Functionality • Load the DSK • Initialize RTDX • Create DTMF samples • GUI Functionality • Load the DSK • Initialize RTDX • Create DTMF samples •](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-16.jpg)
GUI Functionality • Load the DSK • Initialize RTDX • Create DTMF samples • Transmit them to PC Sound Card • Display Dialed and Dtected Digits for comparison © 2007 Texas Instruments Inc, Slide 16
![The System Transmitted Digit GUI Sound Card USB Reported Digit (RTDX) © 2007 Texas The System Transmitted Digit GUI Sound Card USB Reported Digit (RTDX) © 2007 Texas](http://slidetodoc.com/presentation_image_h/a5201028ea0cb1537bb803093d64bc7f/image-17.jpg)
The System Transmitted Digit GUI Sound Card USB Reported Digit (RTDX) © 2007 Texas Instruments Inc, Slide 17
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