DWT BASED OFDM WITH INDEX MODULATION FOR PERFORMANCE ENHANCEMENT IN THE PRESENCE OF CFO

摘要

Inspired by the high spectral efficiency improvement of the Spatial Modulation (SM), Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) was recently proposed and expected to be one of the key technologies of 5G systems. This novel transmission technique incorporates the index of active subcarriers to convey additional information. Similar to conventional OFDM, Carrier Frequency Offset (CFO) is considered as a dominant performance degrading cause of OFDM-IM system. In this paper, Discrete Wavelet Transform (DWT) based OFDM-IM is announced to improve the performance of the conventional OFDM-IM affected by CFO. To this purpose, DWT based OFDM-IM performance in terms of Bit Error Rate (BER) is compared to the original OFDM-IM based on Fast Fourier Transform (FFT) in the presence of CFO. Simulation results are provided to prove the performance enhancement of our proposed system over Rayleigh fading channel.