B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

11 . 9 MATLAB Exercises 653
% can be turned on or off by inputting jamming=l or 0
% Non-coherent MFSK detection
% only needs to compare the magnitude of each frequency bin .
%
clear;clf
n=lOOOO;
L=8;
Lh=l ;
%Number of data symbols in the simulation
% Number of frequency bands
% Number of hops per symbol (bit)
m=l ;
% Number of users
% Generating information bits
s_data=round (rand (n,m) );
% Turn partial band jamming on or off
jamming=input ('jamming=? (Enter 1 for Yes , 0 for No ) ');
% Generating random phases on the two frequencies
xbasel= [exp (j*2 *pi* rand (Lh*n, 1 ))];
xbase0= [exp{j*2 *pi* rand (Lh*n, 1 ))];
% Modulating two orthogonal frequencies
xmodsig= [kron ( s_data,ones (Lh, 1) ) .*xbasel kron( (l-s_data) ,ones (Lh, l) ) .*xbas,
clear xbaseO xbasel;
% Generating a random hopping sequence nLh long
Phop=round (rand (Lh*n, l)* (L-1) )+1; % PN hopping pattern ;
Xsiga=sparse (l:Lh*n, Phop ,xmodsig (:,1));
Xsigb=sparse (l:Lh*n, Phop ,xmodsig (:,2 ));
% Generating noise sequences for both frequency channels
noisel=randn (Lh*n,l)+j*randn (Lh*n, l) ;
noise2=randn (Lh*n,l)+j *randn (Lh*n, 1) ;
Nsiga=sparse (l:Lh*n, Phop ,noisel);
Nsigb=sparse (l:Lh*n, Phop ,noise2);
clear noisel noise2 xmodsig;
BER= [] ;
BER_az= [J;
% Add a jammed channel (randomly picked)
if (jamming )
nch=round (rand* (L- 1) )+1;
Xsiga(:,nch) =Xsiga(:,nch) *O;
Xsigb(:,nch) =Xsigb(:,nch) *O;
Nsiga(:,nch) =Nsiga(:,nch) *O;
Nsigb(:,nch) =Nsigb(: ,nch) *O;
end
% Generating the channel noise (AWGN )
for i=l :10,
Eb2N (i)= i;
Eb2N_num=10 A (Eb2N(i)/10) ;
Var_n=l/ (2*Eb2N_num) ;
signois=sqrt (Var_n) ;
ychl=Xsiga+s ignois*Nsiga ;
ych2=Xsigb+signois*Nsigb ;
% Non-coherent detection
%(Eb/N in dB)
% Eb/N in numeral
%1/SNR is the noise variance
% standard deviation
% AWGN complex channels
% AWGN channels
for kk=O :n-1,
Yvecl= []; Yvec2= [];
for kk2=1 :Lh,
Yvecl= [Yvecl ychl ( kk*Lh+kk2 ,Phop (kk*Lh+kk2 ))];
Yvec2=[Yvec2 ych2 ( kk* Lh+kk2 ,Phop (kk*Lh+kk2 ))];