I have this error, and I don't know how to solve it.Can someone help me please?

Error in p5_6_Simulate_Ceiling_Bounce_Model_and_Eye_Diagram (line 32)

channel_output = conv(Tx_signal,h,'same');

[M]

Can you please post the code that causes this error and the entire error message?

[KALYAN ACHARJYA]

Share the code, it would be helpful to answer the question exactly.

[Alexandra Diaconu]

The code causing the error: %Pulse shaping function (rectangular pulse); channel_output = conv(Tx_signal,h,'same');

And the error message: >> p5_6_Simulate_Ceiling_Bounce_Model_and_Eye_Diagram Error using conv (line 27) A and B must be vectors.

Error in p5_6_Simulate_Ceiling_Bounce_Model_and_Eye_Diagram (line 32) channel_output = conv(Tx_signal,h);

[M]

What are Tx_signal and h ? The error message says they must be vectors.

[Alexandra Diaconu]

Tx is a signal generator. the entire code is:

Rb=200e6;
% Bit rate
Tb=1/Rb;
% bit duration
sig_length = 1e3;
% number of bits
nsamp = 10;
% samples per symbols
Tsamp = Tb/nsamp;
% sampling time
%%*****Channel Impulse response (using Ceiling bounce model)*************
Dt = 0.5;
% Normalized delay spread
Drms = Dt*Tb;
%RMS delay spread
a = 12*sqrt(11/13)*Drms;
K = 30*nsamp;
% number of channel taps
k = 0:K;
h = ((6*a^6)./(((k*Tsamp) + a).^7));
% channel impulse response
h = h./sum(h);
% normalizing for conservation of energy
% **************** filter definitions****************
pt = ones(1,nsamp);
% tranmitter filter
c = conv(pt,h,'same');
OOK = randi(1,sig_length);
% random signal generation
Tx_signal = rectpulse(OOK,nsamp);
%Pulse shaping function (rectangular pulse);
channel_output = conv(Tx_signal,h,'same');
% channel output
eyediagram(channel_output, 3*nsamp);

Answer 1

[M]

The problem is that Tx_signal is not a vector but a matrix of size 1000 x 1000.

From the help of conv function:

C = conv(A, B) convolves vectors A and B..

You can look at conv2:

C = conv2(A, B) performs the 2-D convolution of matrices A and B.

[Alexandra Diaconu]

Thank you so much. It's ok now.

[M]

you're welcome.

Answer 2

[KALYAN ACHARJYA]

The complete code is available in this Book

Optical Wireless Communications: System and Channel Modelling with MATLAB By Z. Ghassemlooy, W. Popoola, S. Rajbhandari

[Alexandra Diaconu]

I have the code from the book but it doesn't work properly.

[KALYAN ACHARJYA]

In the following lines more terms there

pt = ones(1,nsamp);
Ensure that Tx_signal and h both should be the vector to avoid the error.

Answer 3

[Walter Roberson]

OOK = randi(1,sig_length);

That line says that the rand values should be integers in the range 1 to 1, and that you want sig_length rows and columns of them.

If you want random binary you should use

randi([0 1], 1, sig_length)

[Alexandra Diaconu]

I modified, and it works. Thanks.