Title: Performance analysis of QAM-modulation parameters on FFT-OFDM system over Doppler frequency fading channels

Authors: Haitham Jabbar Taha, M.F.M. Salleh

Addresses: School Electrical and Electronic Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang, Malaysia. ' School Electrical and Electronic Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang, Malaysia

Abstract: The typical subcarrier modulation schemes used in orthogonal frequency division multiplexing (OFDM) system includes: binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM). This paper analyses the performance of OFDM system that uses various number of modulation QAM constellation points over various fading channels. Simulation is done for various numbers of QAM (8 to 64-points) and with various Doppler frequency values (5 to 500 Hz) over flat and frequency selective fading channels. Results show that the best performance of OFDM system is with the number of QAM of 8 and maximum Doppler shift (MDS) of 5 Hz at all channels.

Keywords: orthogonal frequency division multiplexing; OFDM; quadrature amplitude modulation; QAM; Doppler frequency; maximum Doppler shift; MDS; fading channels; simulation.

DOI: 10.1504/IJICT.2011.039522

International Journal of Information and Communication Technology, 2011 Vol.3 No.1, pp.40 - 52

Published online: 06 Apr 2011 *

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