[matlab] matlab simulates digital bandpass transmission system ask, PSK, FSK system

Catalog

1、ASK、 PSK、 FSK System

2、 wave form

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1、ASK、 PSK、 FSK System

clear all;
clc;
A = 1; % Carrier amplitude 
fc = 4; % Carrier frequency 
N_sample = 20;
Ts = 1; % Symbol interval 
dt = Ts/(fc*N_sample); % Waveform sampling interval 
N = 1000; % Number of symbols 
t = 0:dt:(N*Ts-dt);
T = dt*length(t);
Lt = length(t);
% ========  baseband signal  ========
d = sign(randn(1,N)); % Generate bipolar code 
dd = sigexpand((d+1)/2,fc*N_sample);% Generate unipolar codes and interpolate 
gt = ones(1,fc*N_sample); %NRZ  wave form 
d_NRZ = conv(dd,gt);