MATLAB Source Code Example for Unipolar Return-to-Zero (RZ) Line Coding

Below is a MATLAB source code example for generating Unipolar Return-to-Zero (RZ) line coding:

% Define binary sequence using random source generator

N = 100; % Sequence length parameter

bits = randsrc(1,N,[0 1]); % Generate random binary sequence (0s and 1s)

% Encoding process with 2PAM modulation conversion

polar = 2*bits-1; % Convert binary to polar format (0→-1, 1→+1) using 2-level Pulse Amplitude Modulation

nrz = zeros(1,2*N); % Initialize Non-Return-to-Zero waveform array

nrz(1:2:end) = polar; % Assign modulated symbols to odd-index positions

nrz(2:2:end) = polar; % Duplicate symbols to even-index positions for NRZ encoding

rz = zeros(1,2*N); % Initialize Return-to-Zero waveform array

rz(1:2:end) = polar; % Assign modulated symbols to odd-index positions

rz(2:2:end) = -polar; % Assign inverted symbols to even-index positions for RZ encoding (returns to zero between bits)

% Signal visualization using subplot arrangement

t = linspace(0,2*pi*length(nrz),length(nrz)); % Create time axis for plotting

subplot(3,1,1); plot(t,nrz); title('NRZ Waveform'); % Display Non-Return-to-Zero signal

subplot(3,1,2); plot(t,rz); title('RZ Waveform'); % Display Return-to-Zero signal with zero-level transitions

subplot(3,1,3); plot(t,polar); title('Polar Signal'); % Display original polar modulated sequence