A Novel Analytical OFDM Modulation Framework using Wavelet Transform with Window Function in the Hilbert space

Abstract

Abstract Orthogonal frequency-division multiplexing (OFDM) technology has been applied in various wireless systems because OFDM approaches can transmit data with high capacity and high data rate. However, in the modern OFDM system, an efficient synchronization between transmitter and receiver is critical to avoid the inter symbol interference (ISI) for matching the huge demand of data in the Big Data era. The existing researches applied fast Fourier transform (FFT) for synchronization and symbol time recovery; however, these approaches resulted in a degraded performance in received signal quality, particularly in low-frequency carrier transmitting by losing the orthogonal characteristic of OFDM signal. To address this challenge, in this paper, we propose a novel analytical OFDM system that conforms to the IEEE 802.11 standard using the window function (rectangular waveform with roll-off characteristics) in the transmitter. The proposed OFDM framework eliminates the spectral sidelong of OFDM. Also, we design the timing recover system using Wavelet transform to extract the OFDM symbol frame signal in Hilbert space. The evaluation results demonstrate the bit error rate (BER) performance of the proposal in Additive white Gaussian noise (AWGN) for symbol data by using Wavelet transform to extract the band limited signal from the receiver side. In addition, we apply an IEEE 802.11 standard-conformed framing sequence and show that the BER performance is improved with the proposed OFDM transceiver synchronization model using Wavelet signal denoising in the same channel of AWGN.