Title: Semi-blind estimation of CFO and channels for STBC-OFDM system

Authors: Mokhtar Besseghier; Ahmed Bouzidi Djebbar

Addresses: Département d'Electronique, Faculté des Sciences et de la Technologie, Université Mustapha Stambouli, Mascara, Algeria; Laboratoire TTNS, Université Djillalil Liabes de Sidi Bel Abbes, Algeria ' Laboratoire TTNS, Université Djillalil Liabes de Sidi Bel Abbes, Algeria

Abstract: Space time block coding-orthogonal frequency division multiplexing (STBC-OFDM)-based multi input multi output (MIMO) system has been shown to be robust against non ideal operating conditions such as antenna correlation, channel estimation errors, and Doppler effects. But, the latter suffers from carrier frequency offset (CFO) which makes channels estimation more challenging. In this paper, we propose joint semi-blind CFO and channels estimators based on modified-multiple signal classification (M-MUSIC) algorithm for STBC-OFDM system over MIMO channels. Channel state information can be estimated at the receiver using pilot symbols embedded in each transmission block. To this end, we propose to encode pilot symbols by a specific space-time block coder (S-STBC) while information symbols are encoded by Alamouti-based space-time block coding (A-STBC). MUSIC-based estimation algorithms are characterised by a high computational complexity. To overcome this drawback, we derive an iterative algorithm which leads to low complexity, high performance CFO and channels estimation. The performance of our algorithms is compared with existing approach by simulations.

Keywords: Alamouti; carrier frequency offset; CFO; channels estimation; MUSIC; virtual subcarriers; VSCs; pilot symbols.

DOI: 10.1504/IJCAET.2022.10048158

International Journal of Computer Aided Engineering and Technology, 2022 Vol.16 No.4, pp.450 - 467

Received: 29 May 2019
Accepted: 10 Oct 2019

Published online: 06 Jul 2022 *

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