Title: Performance evaluation of ICI self-cancellation schemes in fractional wavelet-based OFDM system

Authors: R. Ayeswarya; N. Amutha Prabha

Addresses: School of Electrical Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu, India ' School of Electrical Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu, India

Abstract: The widely used multi carrier modulation technique in the current wireless scenario is orthogonal frequency division multiplexing (OFDM). It is severely affected by frequency offsets and leads to inter carrier interference (ICI). Fractional wavelet transforms (FrWT)-based OFDM model is proposed to mitigate the effect of ICI by its orthogonal fractional wavelets. The performance of FrWT involved OFDM model is comparatively analysed through various mapping schemes of ICI self-cancellation in order to mitigate frequency offsets. This system overcomes the drawback of ICI self-cancellation and shows improved bandwidth efficiency without any cyclic prefix. Simulation results are carried out for the proposed model and compared with exiting Fourier transform and wavelet transform-based OFDM system. The analysis is performed for a range of normalised frequency offsets values. The proposed model performance is tested with various mapping schemes against a frequency offset of 0.05. It is proved that FrWT-based OFDM with ICI self-cancellation gives reduced bit error rate (BER) of 10^–5 at 8 dB signal to noise ratio (SNR). From various graphs, it states that weighted conjugated transformation results in effective mitigation of ICI with BER achievement of 10-4.4 at frequency offset of 0.1.

Keywords: bit error rate; BER; frequency offsets; fast Fourier transform; FFT; fractional wavelet transforms; FrWT; ICI self-cancellation; orthogonal frequency division multiplexing; OFDM.

DOI: 10.1504/IJITST.2020.109534

International Journal of Internet Technology and Secured Transactions, 2020 Vol.10 No.5, pp.552 - 564

Received: 07 Sep 2018
Accepted: 18 Nov 2018
Published online: 15 Sep 2020 *

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