This is my assignment that's due March 17th 8:00 p.m. I tried a lot but couldn't get it. Could you please do this assignment for me? I would not copy and paste your work, I would understand it and then write my own code. I'd really appreciate it.
Thank You.sirat
Background The touch-tone phone uses combinations of sounds of two frequencies to encode phone numbers. The mapping of the frequencies to numbers and letters is given below: Frequency (Hz) 1209 1336 1477 697 1 ABC 2 DEF 3 770 GHI 4 JKL 5 MNO 6 852 PRS 7 TUV 8 WXY 9 941 * 0 # Therefore, for example, the number 2 (and letters A, B and C) is represented by the sum of equal-amplitude 697 and 1336 Hz sinusoids. A 0.25 sec-long burst of the tone digitized at 8 kHz sampling frequency can be constructed and tested via the following Matlab commands: f1=697;%row frequency, unit=[Hz] f2=1336; %column frequency, [Hz] fs=8000; %sampling frequency, [Hz] duration=0.25; %duration of signal, [sec] t=[0:(1/fs):duration]; %time variable, (1/fs)=sampling period A1=0.5;%amplitude of 1st sinusoid p1=0;%phase of 1st sinusoid, need not be 0 A2=0.5;%amplitude of 2nd sinusoid, need not be the same as A1 p2=0;%phase of 2nd sinusoid, need not be the same as p1 tone=A1*cos(2*pi*f1*t+p1)+A2*cos(2*pi*f2*t+p2); sound(tone,fs); % test the tone by sounding it -- optional For BOTH parts, the following criteria must be met to receive any point: 1. Must use principles of Fourier series (i.e., projection or inner product with sinusoidal basis functions). Using other techniques like Fourier transform will forfeit your points. 2. To avoid mindless coding, only codes of less than 80 lines will be accepted for each Parts I and II. 3. DO NOT use Matlab’s built-in functions other than basic arithmetic and flow control commands. If you are not sure if a function is prohibited, ask. Part I: Basic decoding (5 Points) Load the file data.mat into Matlab. The file consists of 2 variables, tones and fs. Each row of tones contains the tone of a single-digit phone number that is digitized at frequency fs. The goal here is to decode each row of tones into its corresponding number using principles of Fourier series. Since each tone is essentially a combination of sinusoids of 7 different frequencies and appropriate amplitudes (including zero), the exercise is equivalent to finding the amplitudes via projecting the tone onto each of the possible frequencies. Therefore, use Matlab to compute the coefficients of the 7 frequencies. You may look up the encoded number from the mapping table via visual inspection for Part I, but not for Part II. Extra credit points toward quiz or homework grades can be earned by the following: · Explanation of approach (1 points) -- “Think before you code!!” · Correct decoding of numbers (3 points) · Adequate documentation of Matlab code (1 point) Part II: Advanced decoding (5 Points) Due to noise, real sinusoidal signals may not have exact amplitude, phase or duration, albeit it can be assumed that their frequencies do not change. The goal here is write a thoroughly tested user-defined function that takes in a single tone (assuming digitized at 8000 Hz), performs the necessary decoding automatically, and returns the numeric decoded number. To facilitate grading, use tone as your input variable and out as the output variable. As such, assuming your function is called touch_decode, its first line should be: function out = touch_decode(tone) Submit your function as an M-file electronically. It will be tested against 100 randomly generated test tones, and you will receive points according to the number of correct answers: · Adequate description of approach and documentation of Matlab code (1 point each) · Accuracy: 100% (3 points); 98-99% (2 points); 95-97% (1 point); less than 95% or run-time error (no point)