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

594 PERFORMANCE ANALYSIS OF DIGITAL COMMUNICATION SYSTEMS
the same BER from simulation, the three different polar modulations require drastically different amount
of channel bandwidth.
COMPUTER EXERCISE l 0.2: ON-OFF BINARY SIGNALING
Next, we present an exercise that implements and tests the on-off signaling as well as a more generic
orthogonal type of signaling. Recall that on-off signaling is a special form of orthogonal binary signaling.
MATLAB program Ex10_2 .m will measure the receiver BER of both signaling schemes.
% MATLAB PROGRAM <Exl0_2 .m>
% This Matlab exercise <Ex10_2 .m> generate
% on/off baseband signals using root-raised cosine
% pulseshape (rolloff factor = 0.5 ) and orthogonal baseband
% signal before estimating the bit error rate (BER) at dif ferent
% Eb/N ratio for display and comparison
clear;clf
L=l000000;
% Total data symbols in experiment is 1 million
% To display the pulse shape , we oversample the signal
% by factor of f_ovsamp=B
f_ovsamp=16;
% Oversampling factor vs data rate
delay_rc=3 ;
% Generating root-raised cosine pulseshape (rolloff factor 0.5)
prcos=rcosflt ([ 1 ], 1, f_ovsamp , 'sqrt ', 0.5, delay_rc );
prcos=prcos (l:end-f_ovsamp+l) ;
prcos=prcos/norm (prcos);
pcmatch=prcos (end : -1:1) ;
% Generating a rectangular pulse shape
psinh=sin ([0:f_ovsamp-l]*pi/f_ovsamp) ;
psinh=psinh/norm (psinh) ;
phmatch=psinh (end:- 1:1) ;
% Generating a hal f-sine pulse shape
psine=sin ([0:f_ovsamp- 1] *2*pi/f_ovsamp) ;
psine=psine/norm (psine );
psmatch=psine (end : -1:1) ;
% Generating random signal data for polar signaling
s_data=round (rand(L, l) );
% upsample to match the 'fictitious oversampling rate '
% which is f_ovsamp /T (T=l is the symbol duration)
s_up=upsample ( s_data, f_ovsamp) ;
s_cp=upsample (l -s_data, f_ovsamp) ;
% Identify the decision delays due to pulse shaping
% and matched filters
delayrc=2*delay_rc* f_ovsamp ;
delayrt=f_ovsamp-1;
% Generate polar signaling of different pulse-shaping
xrcos=conv ( s_up,prcos) ;
xorth=conv (s_up,psinh) +conv (s_cp ,psine) ;
t= (l:200) /f_ovsamp ;
figure (l)
subplot (211)
figwavel=plot (t,xrcos (delayrc /2 : delayrc/2+199) );
title(' (a) On/off root-raised cosine pulse. ');