Help in error in matlab code

Hello everyone,

I have written a matlab code for BPSK modulation. Here in the program, I have first generated random binary bits. Modulated the bits with BPSK modulation. Added noise to the bpsk modulated signal. My matlab code is as follows:

clc;
close all;
clear all;
no_of_bits=10;
no_of_samples=10;
threshold = 0.5;
A = rand(1,no_of_bits); % Generate a random sequence
for i=1:no_of_bits
if (A(i)>=threshold)
A(i)=1;
else
A(i)=0;
end
end
d = A(1:no_of_bits) % Binary sequence
% BPSK modulation
Tb = 1; % Bit duration
fc = 3/Tb; % Carrier frequency
t1=linspace(0, 1, no_of_samples);
t2=t1/fc;
M=2; % Number of symbols
theta=([0:M-1]*2*pi)/M; % Reference phase values
PhaseOsc1=cos(2*pi*fc*t2)
PhaseOsc2=cos(theta) % Carrier waveform
b = 2*d-1 % Bipolar sequence
for i=1:no_of_bits
for j=1:no_of_samples
b1(j)=b(i)
end
bpskmod=b1.*PhaseOsc1.*PhaseOsc2; % Modulated bpsk waveform
end
noise = randn(1,no_of_samples); % Noise addition
recbpsk = bpskmod + noise;

After running the above program, it gives me following error:
Error in ==> abc1 at 30
bpskmod=b1.*PhaseOsc1.*PhaseOsc2; % Modulated bpsk waveform

Kindly help me in correcting the above error.

Hi.. I have the code, which works for me.. you can try this.

d=[1 0 1 0 1 ]; % Data sequence
b=2*d-1; % Convert unipolar to bipolar
T=1; % Bit duration
Eb=T/2; % This will result in unit amplitude waveforms
fc=1; % Carrier frequency
t=linspace(0,5,10000); % discrete time sequence between 0 and 5*T (1000 samples)
N=length(t); % Number of samples
Nsb=N/length(d); % Number of samples per bit
dd=repmat(d',1,Nsb); % replicate each bit Nsb times
bb=repmat(b',1,Nsb);
dw=dd'; % Transpose the rows and columns
dw=dw)'; % Convert dw to a column vector (colum by column) and convert to a row vector
bw=bb';
bw=bw)'; % Data sequence samples
w=sqrt(2*Eb/T)*cos(2*pi*fc*t); % carrier waveform
bpsk_w=bw.*w; % modulated waveform

% plotting commands follow

subplot(4,1,1);
plot(t,dw); axis([0 5 -1.5 1.5])

subplot(4,1,2);
plot(t,bw); axis([0 5 -1.5 1.5])

subplot(4,1,3);
plot(t,w); axis([0 5 -1.5 1.5])

subplot(4,1,4);
plot(t,bpsk_w,'.'); axis([0 5 -1.5 1.5])
xlabel('time')


If you find any query in this.. tell me.

- - - Updated - - -

Hi.. I have the code, which works for me.. you can try this.

d=[1 0 1 0 1 ]; % Data sequence
b=2*d-1; % Convert unipolar to bipolar
T=1; % Bit duration
Eb=T/2; % This will result in unit amplitude waveforms
fc=1; % Carrier frequency
t=linspace(0,5,10000); % discrete time sequence between 0 and 5*T (1000 samples)
N=length(t); % Number of samples
Nsb=N/length(d); % Number of samples per bit
dd=repmat(d',1,Nsb); % replicate each bit Nsb times
bb=repmat(b',1,Nsb);
dw=dd'; % Transpose the rows and columns
dw=dw)'; % Convert dw to a column vector (colum by column) and convert to a row vector
bw=bb';
bw=bw)'; % Data sequence samples
w=sqrt(2*Eb/T)*cos(2*pi*fc*t); % carrier waveform
bpsk_w=bw.*w; % modulated waveform

% plotting commands follow

subplot(4,1,1);
plot(t,dw); axis([0 5 -1.5 1.5])

subplot(4,1,2);
plot(t,bw); axis([0 5 -1.5 1.5])

subplot(4,1,3);
plot(t,w); axis([0 5 -1.5 1.5])

subplot(4,1,4);
plot(t,bpsk_w,'.'); axis([0 5 -1.5 1.5])
xlabel('time')


If you find any query in this.. tell me.