# Generate binary signal and convert to integer in Matlab

I am going to test an algorithm and need a test signals.

My first test signal is a binary signal of 1 or -1. I was thinking about how to implement such a sequence in matlab and wrote this:

binary_data = rand(1,M) > 0.5;
b = 2.*binary_data - 1;


My next step is:

dataInMatrix = reshape(b,length(b)/k,k); % reshape data into binary k-arrays, k=log2(M), M -size of signal constelation
dataSymbolsIn = bi2de(dataInMatrix);


error: Expected input number 1, binary vector b, to be nonnegative.

How to convert such binary sequence to integer if i need create symbols?

EDIT 1.

Guys, I have generated a test signal and it look like this:

• i generate a sequence 1 or -1
• use a raised cosine filter

How can I get a blue lines...show samples ( digital signal)?

• Hi. This is not a signal processing but a pure matlab programming question (Stackoverflow might be a better place), and honestly, it reads like you really should start with the tutorial that comes with matlab. – Marcus Müller Feb 24 at 18:50
• @Marcus Muller. Ali23's question certainly is a signal processing question! He needs help generating digital test signals. Rather than belittling Ali23, you should try to help him. – Richard Lyons Feb 25 at 10:52
• Hi @RichardLyons you're right, this question has come a long way since it was stated (back then it was really just containing a=ones(1,N): signal = [ a -a a -a];, and that really told me that prior to tackling the signal processing, Ali23 needed to get familiar with the tools :) I didn't mean to belittle! – Marcus Müller Feb 25 at 11:36
• Hi @Marcus Muller. Thanks for your comment. I didn't intend to sound "too strong". I merely want the very smart guys on this web site to be as friendly and helpful as they can be. – Richard Lyons Feb 25 at 16:02

@Ali23. If by "How can I get a blue lines?" you mean how to generate samples of the your red curve, try the following:

m = [1, -1, -1, 1 1, -1]; m = [m m m m];

N = length(m);

M = 10; mup=zeros(1,NM); mup(1:M:NM)=m; % oversample by M

h = hamming(M); % blip pulse of width M

x = filter(h,1,mup); % convolve pulse shape with 'm' data

t = 1/M:1/M:length(x)/M;

figure(1), subplot(2,1,1), plot(0:0.1:0.9,h)

subplot(2,1,2), plot(t,x)

In the above I used a simple hamming sequence rather than the impulse response of a RRC filter. (You should use the impulse response of a RRC filter.) The key point here is that you have to upsample (zero stuffing) the 'm' sequence before you apply it to the filter.

@Ali23. your 'binary_data = rand(1,M) > 0.5;' command generates "logical" data. Try using 'binary_data = int8(rand(1,M));' and see if that helps you.