Skip to main content
Login Home Wireless Communication Modulation MATLAB Beamforming Project Ideas MIMO Computer Networks

MATLAB Code for Pulse Amplitude Modulation (PAM) and Demodulation


 

Pulse Amplitude Modulation (PAM) & Demodulation of an Analog Message Signal

MATLAB Script

clc;

clear all;

close all;

fm= 10; % frequency of the message signal

fc= 100; % frequency of the carrier signal

fs=1000*fm; % (=100KHz) sampling frequency (where 1000 is the upsampling factor)

t=0:1/fs:1; % sampling rate of (1/fs = 100 kHz)

m=1*cos(2*pi*fm*t); % Message signal with period 2*pi*fm (sinusoidal wave signal)

c=0.5*square(2*pi*fc*t)+0.5; % square wave with period 2*pi*fc

s=m.*c; % modulated signal (multiplication of element by element)

subplot(4,1,1);

plot(t,m);

title('Message signal');

xlabel ('Time');

ylabel('Amplitude');

subplot(4,1,2);

plot(t,c);

title('Carrier signal');

xlabel('Time');

ylabel('Amplitude');

subplot(4,1,3);

plot(t,s);

title('Modulated signal');

xlabel('Time');

ylabel('Amplitude');

%demdulated

d=s.*c; % At receiver, received signal is multiplied by carrier signal

filter=fir1(200,fm/fs,'low'); % low-pass FIR filter which order is 200

% here fm is the cut-off frequency and the fs is the sampling frequency

original_t_signal=conv(filter,d); % convolution of demodulated signal with filter %coefficient

t1=0:1/(length(original_t_signal)-1):1;

subplot(4,1,4);

plot(t1,original_t_signal);

title('demodulated signal');

xlabel('time');

ylabel('amplitude');

web('https://www.salimwireless.com/search?q=pulse%20amplitude%20modulation', '-browser');

 Output

 

Copy the code from here

 


Another Code for Pulse Amplitude Modulation and Demodulation of an Analog Message Signal 

MATLAB Script

 clc;
clear;
close all;

% Parameters
messageFrequency = 2;   % Message frequency in Hz
carrierFrequency = 20;  % Carrier frequency in Hz
samplingFrequency = 1000; % Sampling frequency in Hz
duration = 1;           % Signal duration in seconds
A = 1;                  % Amplitude of the signals

% Time vector
t = 0:1/samplingFrequency:duration;

% Message signal (sinusoidal)
messageSignal = A * sin(2 * pi * messageFrequency * t);

% Carrier signal (square wave)
carrierSignal = A * square(2 * pi * carrierFrequency * t);

% PAM signal
pamSignal = messageSignal .* (carrierSignal > 0);

% Plotting
figure;
subplot(3,1,1);
plot(t, messageSignal);
title('Message Signal');
xlabel('Time (s)');
ylabel('Amplitude');

subplot(3,1,2);
plot(t, carrierSignal);
title('Carrier Signal');
xlabel('Time (s)');
ylabel('Amplitude');

subplot(3,1,3);
plot(t, pamSignal);
title('PAM Signal');
xlabel('Time (s)');
ylabel('Amplitude');
web('https://www.salimwireless.com/search?q=pulse%20amplitude%20modulation', '-browser');

Copy the Code from here

 

Pulse Amplitude Modulation (PAM) & Demodulation for Digital Data

% The code is written by SalimWireless.Com
clc;
clear;
close all;


% PAM Modulation and Demodulation Example


% Parameters
M = 8; % PAM order (8-PAM)
numSymbols = 100; % Number of symbols to transmit
Fs = 1000; % Sampling frequency
T = 1; % Symbol duration


% Generate random data
data = randi([0 M-1], 1, numSymbols); % Random data symbols


% PAM Modulation
% Map the data symbols to PAM levels
pamLevels = linspace(-M + 1, M - 1, M); % PAM levels
modulatedSignal = pamLevels(data + 1); % Map data to PAM levels


% Create a time vector
t = 0:1/Fs:T*numSymbols-1/Fs;


% Upsample and create PAM signal
upsampledSignal = zeros(1, length(t));
for i = 1:numSymbols
upsampledSignal((i-1)*Fs+1:i*Fs) = modulatedSignal(i);
end


% Add some noise
snr = 20; % Signal-to-noise ratio
noisySignal = awgn(upsampledSignal, snr, 'measured');


% PAM Demodulation
% Sample the noisy signal at symbol rate
receivedSymbols = noisySignal(1:Fs:end);


% Map received symbols to nearest PAM level
demodulatedData = zeros(1, numSymbols);
for i = 1:numSymbols
[~, demodulatedData(i)] = min(abs(receivedSymbols(i) - pamLevels));
end


% Plotting
figure;
subplot(4,1,1);
stem(data);
title('Original Data');
xlabel('Time (s)');
ylabel('Amplitude');


subplot(4,1,2);
plot(t, upsampledSignal);
title('Transmitted PAM Signal');
xlabel('Time (s)');
ylabel('Amplitude');


subplot(4,1,3);
plot(t, noisySignal);
title('Received Noisy PAM Signal');
xlabel('Time (s)');
ylabel('Amplitude');


subplot(4,1,4);
stem(demodulatedData);
title('Demodulated Data');
xlabel('Symbol Index');
ylabel('PAM Level');
grid on;


% Display results
disp('Original Data:');
disp(data);
disp('Demodulated Data:');
disp(demodulatedData);
web('https://www.salimwireless.com/search?q=pulse%20amplitude%20modulation', '-browser');

Output






Copy the MATLAB Code from here



Simulation Results for comparison of PAM, PWM, PPM, DM, and PCM

 
 
 
 

 
  
 

 
 
 
 
 

 
 
 

Explore Signal Processing Simulations

Further Reading

  1. Pulse Amplitude Modulation and Demodulation theory
  2. Is PAM a Digital Modulation Technique ?
  3. Pulse Width Modulation (PWM) and Demodulation
  4. Pulse Position Modulation (PPM) and Demodulation
  5. Delta Modulation and demodulation
  6. Pulse Code Modulation (PCM)
  7. Quantization Signal to Noise Ration (Q-SNR)
  8. MATLAB Code for Pulse Width Modulation and Demodulation
  9. MATLAB Code for Pulse Position Modulation (PPM) and Demodulation
  10. MATLAB Code for Pulse Code Modulation (PCM) and demodulation

People are good at skipping over material they already know!

View Related Topics to







Admin & Author: Salim

s

  Website: www.salimwireless.com
  Interests: Signal Processing, Telecommunication, 5G Technology, Present & Future Wireless Technologies, Digital Signal Processing, Computer Networks, Millimeter Wave Band Channel, Web Development
  Seeking an opportunity in the Teaching or Electronics & Telecommunication domains.
  Possess M.Tech in Electronic Communication Systems.


Contact Us

Name

Email *

Message *

Popular Posts

Constellation Diagrams of M-ary QAM | M-ary Modulation

๐Ÿ“˜ Overview of QAM ๐Ÿงฎ MATLAB Code for m-ary QAM (4-QAM, 16-QAM, 32-QAM, ...) ๐Ÿงฎ Online Simulator for M-ary QAM Constellations ๐Ÿ“š Further Reading ๐Ÿ“‚ Other Topics on Constellation Diagrams of QAM configurations ... ๐Ÿงฎ MATLAB Code for 4-QAM ๐Ÿงฎ MATLAB Code for 16-QAM ๐Ÿงฎ MATLAB Code for m-ary QAM (4-QAM, 16-QAM, 32-QAM, ...) ๐Ÿงฎ Simulator for constellation diagrams of m-ary PSK ๐Ÿงฎ Simulator for constellation diagrams of m-ary QAM ๐Ÿงฎ Overview of Energy per Bit (Eb / N0) ๐Ÿงฎ Online Simulator for constellation diagrams of ASK, FSK, and PSK ๐Ÿงฎ Theory behind Constellation Diagrams of ASK, FSK, and PSK ๐Ÿงฎ MATLAB Codes for Constellation Diagrams of ASK, FSK, and PSK QAM Unlike this, the M-ary PSK signal is modulated with a different phase-shifted version of the carrier signal and varying amplitude levels. Let me give an example for better comprehension. QAM = ASK +...
Read more

Theoretical vs. simulated BER vs. SNR for ASK, FSK, and PSK

๐Ÿ“˜ Overview ๐Ÿงฎ Simulator for calculating BER ๐Ÿงฎ MATLAB Codes for calculating theoretical BER ๐Ÿงฎ MATLAB Codes for calculating simulated BER ๐Ÿ“š Further Reading   BER vs. SNR denotes how many bits in error are received in a communication process for a particular Signal-to-noise (SNR) ratio. In most cases, SNR is measured in decibel (dB). For a typical communication system, a signal is often affected by two types of noises 1. Additive White Gaussian Noise (AWGN) 2. Rayleigh Fading In the case of additive white Gaussian noise (AWGN), random magnitude is added to the transmitted signal. On the other hand, Rayleigh fading (due to multipath) attenuates the different frequency components of a signal differently. A good signal-to-noise ratio tries to mitigate the effect of noise.  Simulator for calculating BER vs SNR for binary ASK, FSK, and PSK Calculate BER for Binary ASK Modulation The theoretical BER for binary ASK (BASK) in an AWGN channel is...
Read more

BER vs SNR for M-ary QAM, M-ary PSK, QPSK, BPSK, ...

๐Ÿ“˜ Overview of BER and SNR ๐Ÿงฎ Online Simulator for BER calculation of m-ary QAM and m-ary PSK ๐Ÿงฎ MATLAB Code for BER calculation of M-ary QAM, M-ary PSK, QPSK, BPSK, ... ๐Ÿ“š Further Reading ๐Ÿ“‚ View Other Topics on M-ary QAM, M-ary PSK, QPSK ... ๐Ÿงฎ Online Simulator for Constellation Diagram of m-ary QAM ๐Ÿงฎ Online Simulator for Constellation Diagram of m-ary PSK ๐Ÿงฎ MATLAB Code for BER calculation of ASK, FSK, and PSK ๐Ÿงฎ MATLAB Code for BER calculation of Alamouti Scheme ๐Ÿงฎ Different approaches to calculate BER vs SNR What is Bit Error Rate (BER)? The abbreviation BER stands for bit error rate, which indicates how many corrupted bits are received (after the demodulation process) compared to the total number of bits sent in a communication process. It is defined as,  In mathematics, BER = (number of bits received in error / total number of transmitted bits)  On the other hand, SNR ...
Read more

Hybrid Beamforming | Page 2

Beamforming Techniques Hybrid Beamforming... Page 1 | Page 2 | clear all; close all; clc; Nt = 64; Nr = 16; NtRF = 4; NrRF = 4; At both the transmitter and receiver ends, there are four RF chains only for a hybrid beamforming system. Alternatively, every 16 antenna elements on the transmitter side is connected to a single RF chain, while every 4 antenna elements on the receiver side are connected to a single RF chain. Mixers, amplifiers, and other critical wireless communication components make up the RF chain. Now, in the case of hybrid beamforming, there can be four different data streams between the transmitter and receiver, as both sides have four RF chains, each of which is accountable for a separate data stream. For Analog Beamforming: All 64 Tx antenna elements create a beam or focus the resultant correlated signal spread from adjacent antennas to a particular direction. Similarly, it may be used for beam...
Read more

Comparisons among ASK, PSK, and FSK | And the definitions of each

๐Ÿ“˜ Comparisons among ASK, FSK, and PSK ๐Ÿงฎ Online Simulator for calculating Bandwidth of ASK, FSK, and PSK ๐Ÿงฎ MATLAB Code for BER vs. SNR Analysis of ASK, FSK, and PSK ๐Ÿ“š Further Reading ๐Ÿ“‚ View Other Topics on Comparisons among ASK, PSK, and FSK ... ๐Ÿงฎ Comparisons of Noise Sensitivity, Bandwidth, Complexity, etc. ๐Ÿงฎ MATLAB Code for Constellation Diagrams of ASK, FSK, and PSK ๐Ÿงฎ Online Simulator for ASK, FSK, and PSK Generation ๐Ÿงฎ Online Simulator for ASK, FSK, and PSK Constellation ๐Ÿงฎ Some Questions and Answers Modulation ASK, FSK & PSK Constellation MATLAB Simulink MATLAB Code Comparisons among ASK, PSK, and FSK    Comparisons among ASK, PSK, and FSK   Simulator for Calculating Bandwidth of ASK, FSK, and PSK The baud rate represents the number of symbols transmitted per second. Both baud rate and bit rate a...
Read more

Difference between AWGN and Rayleigh Fading

๐Ÿ“˜ Introduction, AWGN, and Rayleigh Fading ๐Ÿงฎ Simulator for the effect of AWGN and Rayleigh Fading on a BPSK Signal ๐Ÿงฎ MATLAB Codes ๐Ÿ“š Further Reading Wireless Signal Processing Gaussian and Rayleigh Distribution Difference between AWGN and Rayleigh Fading 1. Introduction Rayleigh fading coefficients and AWGN, or additive white gaussian noise [↗] , are two distinct factors that affect a wireless communication channel. In mathematics, we can express it in that way.  Fig: Rayleigh Fading due to multi-paths Let's explore wireless communication under two common noise scenarios: AWGN (Additive White Gaussian Noise) and Rayleigh fading. y = h*x + n ... (i) Symbol '*' represents convolution. The transmitted signal  x  is multiplied by the channel coefficient or channel impulse response (h)  in the equation above, and the symbol  "n"  stands for the white Gaussian noise that is added to the si...
Read more

Comparing Baseband and Passband Implementations of ASK, FSK, and PSK

๐Ÿ“˜ Overview ๐Ÿงฎ Baseband and Passband Implementations of ASK, FSK, and PSK ๐Ÿงฎ Difference betwen baseband and passband ๐Ÿ“š Further Reading ๐Ÿ“‚ Other Topics on Baseband and Passband ... ๐Ÿงฎ Baseband modulation techniques ๐Ÿงฎ Passband modulation techniques   Baseband modulation techniques are methods used to encode information signals onto a baseband signal (a signal with frequencies close to zero), allowing for efficient transmission over a communication channel. These techniques are fundamental in various communication systems, including wired and wireless communication. Here are some common baseband modulation techniques: Amplitude Shift Keying (ASK) [↗] : In ASK, the amplitude of the baseband signal is varied to represent different symbols. Binary ASK (BASK) is a common implementation where two different amplitudes represent binary values (0 and 1). ASK is simple but susceptible to noise...
Read more

MATLAB code for BER vs SNR for M-QAM, M-PSK, QPSk, BPSK, ...

๐Ÿ“˜ Overview ๐Ÿงฎ Simulator for m-ary QAM and m-ary PSK ๐Ÿงฎ MATLAB Code for BPSK, M-ary PSK, and M-ary QAM Together ๐Ÿงฎ MATLAB Code for M-ary QAM ๐Ÿงฎ MATLAB Code for M-ary PSK ๐Ÿ“š Further Reading   MATLAB Script for  BER vs. SNR for M-QAM, M-PSK, QPSk, BPSK %Written by Salim Wireless %Visit www.salimwireless.com for study materials on wireless communication %or, if you want to learn how to code in MATLAB clc; clear; close all; % Parameters num_symbols = 1e5; % Number of symbols snr_db = -20:2:20; % Range of SNR values in dB % PSK and QAM orders to be tested psk_orders = [2, 4, 8, 16, 32]; qam_orders = [4, 16, 64, 256]; % Initialize BER arrays ber_psk_results = zeros(length(psk_orders), length(snr_db)); ber_qam_results = zeros(length(qam_orders), length(snr_db)); % BER calculation for each PSK order and SNR value for i = 1:length(psk_orders) psk_order = psk_orders(i); for j = 1:length(snr_db) % Generate random symbols ...
Read more