PCM using matlab

%Sourangsu Banerji %Copyright (c) 2013 %All rights reserved. %For educational purposes. %https://www.mathworks.com/matlabcentral/fileexchange/42167-pulse-code-modulation?focused=3786778&tab=function % Theory: % Pulse Code Modulation % Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard % form of digital audio in computers, Compact Discs, digital telephony and other digital audio applications. In a PCM % stream, the amplitude of the analog signal is sampled regularly at uniform intervals, and each sample is quantized to % the nearest value within a range of digital steps. % PCM streams have two basic properties that determine their fidelity to the original analog signal: the sampling rate, % the number of times per second that samples are taken; and the bit depth, which determines the number of possible % digital values that each sample can take. % clc; clear all; b=input('Enter Quantization Interval:: '); t = 0:0.0005:10; % Representation of the Message Signal x = sin(t); subplot(3,1,1); plot(t,x,'black'); title('Message Signal'); xlabel('Time(s) ---->') ylabel('Amplitude(V) ---->') legend('Message Signal ---->'); grid on % Representation of the Quantized Signal partition = -1:0.1:b; codebook = -1:0.1:(b+0.1); [index,quants] = quantiz(x,partition,codebook); subplot(3,1,2); plot(t,quants); title('Quantized Signal'); xlabel('Samples ---->') ylabel('Amplitude(V) ---->') legend('Quantized Signal ---->'); grid on % Representation of the PCM Signal y = uencode(quants,3); subplot(3,1,3); plot(t,y,'red'); title('PCM Signal'); xlabel('Samples ---->'); ylabel('Amplitude(V) ---->') legend('PCM Signal ---->'); grid on % Add title to the Overall Plot ha = axes ('Position',[0 0 1 1],'Xlim',[0 1],'Ylim',[0 1],'Box','off','Visible','off','Units','normalized', 'clipping' , 'off'); text (0.5, 1,'\bf Pulse Code Modulation ','HorizontalAlignment','center','VerticalAlignment', 'top')