Root Raised Cosine Pulse Shape Based ICI Suppression in OFDM System for Rayleigh Multipath Channel

Khedkar, Ashok; Sumathi, M.; Murugan, M.

doi:10.21817/ijet/2016/v8i6/160806239

Cited by 2 publications

(2 citation statements)

References 7 publications

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“…The CFO destroys the orthogonality relationship between the subcarriers, creating intercarrier interference (ICI) in OFDM systems. ICI is a frequency mismatch between the transmitter and receiver, and this frequency mismatch leads to severe performance degradation in OFDM wireless systems [5,6]. This problem is even more serious in the OFDM-based UWA systems.…”

Section: Introduction *mentioning

confidence: 99%

Proposal for a Doppler Shift Compensation Method Using Non-Uniform FFT with Pilot Carrier Frequency for OFDM-Based Underwater Acoustic Communication Systems

2023

JST: SSAD

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In this paper, we propose a method that uses the non-uniform Fast Fourier Transform (FFT) to compensate for Doppler frequency shifts in orthogonal frequency division multiplexing (OFDM) based underwater acoustic (UWA) communication systems. To estimate the Doppler frequency shift, the paper proposes using a pilot carrier frequency (PCF) that is identified by transmitting with greater power in the frequency domain compared to other subcarriers. This identifier helps estimate both the Doppler frequency shift and the channel. The paper proposes estimating and compensating for the Doppler frequency shift in two steps: Step 1 performs coarse frequency synchronization, where the Doppler frequency shift is determined by using PCF signal. The Doppler shift correction is obtained by re-sampling the received signal, and then interpolating re-sampled signal. However, the Doppler shift compensation in the step 1 cannot correct the phase distortion of the measured PCF signal. Therefore, performing step 2, known as fine frequency synchronization, is necessary. In this step, the correction for the phase distortion is determined based on the phase difference between the two consecutive OFDM signals in one frame. The remaining Doppler frequency shift is adjusted based on the phase deviation, using the non-uniform FFT. By using the non-uniform FFT, the complexity of the ICI compensation is significantly reduced, and the quality of Doppler shift compensation is improved. The experience results show that the transmitted text will be decoded correctly by using the proposed technique

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Section: Introduction *mentioning

confidence: 99%