Table of Contents
ISRN Communications and Networking
Volume 2012 (2012), Article ID 295424, 5 pages
http://dx.doi.org/10.5402/2012/295424
Research Article

Quasi-Orthogonal Time Division Multiplexing and Its Performances in Rayleigh Fading Channels

1School of Electronic Information and Control Engineering, Beijing University of Technology, Beijing, China
2State Key Laboratory of Integrated Services Networks (ISN), Xidian University, Xi'an, China
3Beijing Research Institute of ZTE Corporation, Beijing 100191, China

Received 10 January 2012; Accepted 26 January 2012

Academic Editors: A. Maaref and K. Teh

Copyright Β© 2012 Enchang Sun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper proposes an efficient transmission scheme, Quasi-Orthogonal Time Division Multiplexing (QOTDM), which employs the shift orthogonal property of the pulse function with raised-cosine spectral shape, and the signal waveforms are quasi-orthogonal in time domain. Comparing to orthogonal frequency division multiplexing (OFDM), QOTDM is less sensitive to carrier frequency offset and power amplifier nonlinearities while keeping a similar spectral efficiency with OFDM due to single-carrier characteristics. QOTDM is a suitable consideration for the downlink transmission such as in satellite communications. An upper bound of sample error probability (SER) is derived to evaluate the performance of QOTDM. Comparisons of QOTDM and OFDM in Rayleigh fading channels show that the proposed QOTDM system is better than that of OFDM system in terms of bit error rate (BER) in high 𝐸𝑏/π‘π‘œ regions.