# Phase-shift Keying and Guard Interval

Topics: Phase-shift keying, Modulation, Quadrature amplitude modulation Pages: 2 (591 words) Published: March 30, 2013
Al-Quds University
Faculty of Engineering

Electronics and Computer Engineering Master Program

Second Semester 2012/2013

Assignment: Computer Simulation of OFDM System

It is required to simulate the performance of OFDM system in Additive White Gaussian Noise (AWGN) channel. Particularly, each student should investigate the effect of various parameters such as SNR, cyclic prefix/guard interval, number of subcarriers M, number of Monte-Carlo simulation loop nloop, type of modulation (qammod, pskmod) with different values of modulation levels q. Given the Matlab code that implements the OFDM system in AWGN channel, it is required to prepare a report that includes the following: 1. Study the effect of the length of the guard interval on the BER performance of the system. Provide one Matlab figure (Fig. 1) showing the BER vs SNR performance when the length of the guard interval is M/2, M/4, M/8, M/16, M=1024, nloop=100000, q=4. Comment on the results. 2. Study the effect of number of subcarriers on the BER performance of the system. Provide one Matlab figure (Fig. 2) showing the BER vs SNR performance when the guard interval is M/4, nloop=100000, q=4, and for different number of subcarriers: M=256, M=512, M=1024, M=2048. Comment on the results. 3. Study the effect of the length of the Monte-Carlo simulation loop on the BER performance of the system. Provide one Matlab figure (Fig. 3) showing the BER vs SNR performance when the guard interval is M/4, M=1024, q=4, and for different values of the loop: nloop=10, nloop=1000, nloop=100000, nloop=10000000. Comment on the results. 4. Study the effect of the Quadrature Amplitude Modulation (QAM) with different modulation levels on the BER performance of the system. Provide one Matlab figure (Fig. 4) showing the BER vs SNR performance when the guard interval is M/4, M=1024, nloop=100000, and for different values of modulation levels: “q=4 QAM”,...