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

Figure 10.42
Error probability P P
of PSK, DPSK,
and coherent 10- 1
and noncoherent
FSK.
10-2
t
10-3
Coherent FSK
10.12 MATLAB Exercises 589
10-4
10-5
DPSK
10-6
10-7
10-8
-5 -4 -2 0 2 4 6 8 10 12 14 Eb dB ➔
N '
we saw earlier that DPSK appears similar to PSK for large SNR. Rigorous derivation of
Eq. (10. 147) can be found in the literature. 7
10. 1 2 MATLAB EXERCISES
In this group of computer exercises, we give readers an opportunity to test the implementation
and the performance of basic digital communication systems.
COMPUTER EXERCISE 10.1 : BINARY POLAR SIGNALING WITH DIFFERENT PULSES
In the first exercise, we validate the performance analysis of the binary polar signaling presented
in Section 10.1. Optimum (matched filter) detection are always used at the receiver. In the program
ExlO_l .m, three different pulses are used for polar signaling:
• Rectangular pulse p(t) = u(t) - u(t - T) .
• Half-sine pulse p(t) = sin (JTt/T) [u(t) - u(t - T) ].
• Root-raised cosine pulse with roll-off factor r = 0.5 (or bandwidth 0.75/T) and truncated to duration
of 6T.
% Matlab Program <Exl0_l .m>
% This Matlab exercise <Exl0_l .m> performs simulation of
% binary baseband polar transmission in AWGN channel .
% The program generates polar baseband signals using 3 different
% pulse shapes (root-raised cosine (r= 0.5) , rectangular, half-sine)
% and estimate the bit error rate (BER) at dif ferent Eb/N for display
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=8
f_ovsamp=8;
% Oversampling factor vs data rate
delay_rc=3;
% Generating root-raised cosine pulseshape (rolloff factor 0.5)