A Spectrally Efficient Intercarrier Interference Reduction Scheme for Orthogonal Frequency Division Multiplexing Systems in Low Signal-to-noise Ratio Environment

Abstract

The inherent sensitivity of orthogonal frequency division multiplexing (OFDM) systems to any frequency shift in the signal makes their design very challenging. In OFDM systems, the frequency shift may be due to instability of transmitter/ receiver oscillators or because of fading channel. The frequency shift in the signal destroys the orthogonality among subcarriers and results in intercarrier interference (ICI), which affects the system performance severely. A number of solutions are available to mitigate the effect of ICI. The existing ICI mitigation techniques include frequency equalization, time domain windowing, ICI self-cancellation, coding, etc., Among several ICI reduction methods, ICI self-cancellation scheme has received much attention due to its simplicity. The ICI mitigation schemes that depend on carrier frequency offset (CFO) correction at the transmitter are effective under high signal-to-noise ratio (SNR) scenario and those that depend on CFO estimation and correction at the receiver have additional computational complexity and some sort of data symbol redundancy. In this paper, a bandwidth-efficient ICI reduction method for M-ary QAM signals is proposed. The present method is effective in low SNR environment. This method reduces the effect of ICI and improves the performance of the system in terms of bit error rate. It is shown that the proposed ICI cancellation method considerably outperforms the existing ICI self-cancellation schemes in the presence of small CFO while maintaining the throughput level.

Keywords:

• Frequency offset
• Intercarrier interference cancellation
• Orthogonal frequency division multiplexing system
• System throughput

Additional information

Notes on contributors

Arvind Kumar

Arvind Kumar received his B. Sc. (Maths), B.Tech. (Electronics & Telecommunication Engineering), and M. E. (Control & Instrumentation) degrees in 1992, 1996, and 1999 from Rohilkhand University Bareilly, Allahabad University Allahabad, and MNNIT Allahabad (formerly MNREC Allahabad), respectively. Presently, he is an Asst. Prof. in the Department of Electronics & Communication Engineering N. I. T. Kurukshetra, India. His research interests include communication systems, OFDM systems, and MIMO OFDM systems. E-mail: [email protected]

Rajoo Pandey

Rajoo Pandey received his B. E., M. Tech., and Ph. D., degrees in Electronics & Communication Engineering in 1989, 1991, and 2001 from Government Engineering College, Jabalpur, R. E. C. Kurukshetra, and Indian Institute of Technology, Roorkee, India, respectively. He is an Associate Prof. in the Department of Electronics & Communication Engineering N. I. T. Kurukshetra, India. His research interests include Signal and Image processing, communication systems, OFDM systems, MIMO systems, and neural networks. E-mail: [email protected]