A new algorithm for joint time and phase synchronization in OFDM systems
Yükleniyor...
Dosyalar
Tarih
2000
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
IEEE
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this paper, a computationally efficient algorithm is presented for joint maximum likelihood (ML) timing and carrier phase synchronization of OFDM systems employing M-PSK modulation scheme with additive Gaussian noise, based on the Expectation-Maximization (EM) method. A nondata-aided(NDA) scheme is considered for the joint timing and phase synchronizer which maximizes the low SNR limit of the likelihood function averaged over the MPSK signal constellation. For this, an EM algorithm is derived which estimates the timing offset and the phase rotations of each subcarrier iteratively and which converges to the true ML estimation of the unknown timing and phase. It is shown that the algorithm becomes independent of the signal-to-noise ratio for both low and high SNR cases. The algorithm is applied to the QPSK modulated OFDM systems and-it is concluded that for SNR values greater than 10 dB the convergence is achieved in first iteration and for SNR values less than 10 dB, at most in three iterations. It is also concluded that the convergence is independent of the initial starting points.
Açıklama
Anahtar Kelimeler
Additive noise, Convergence, Gaussian noise, Iterative algorithms, Maximum likelihood estimation, OFDM modulation, Phase estimation, Phase modulation, Signal to noise ratio, Timing, EM algorithm, M-PSK modulation, M-PSK signal constellation, ML estimation, OFDM systems, QPSK, SNR limit, Additive Gaussian noise, Carrier phase estimation, Carrier phase synchronization, Computationally efficient algorithm, Expectation-maximization method, Fading channel, Joint time/phase synchronization, Likelihood function, Maximum likelihood timing synchronisation, Mobile channel, Multipath, Nondata-aided scheme, Phase rotations, Timing offset, Convergence of numerical methods, Land mobile radio, Multipath channels, Optimisation, Phase shift keying, Synchronisation
Kaynak
11th IEEE International Symposium on Personal Indoor and Mobile Radio Communications. PIMRC 2000. Proceedings (Cat. No.00TH8525)
WoS Q Değeri
N/A
Scopus Q Değeri
N/A
Cilt
2
Sayı
Künye
Panayırcı, E. (2000). A new algorithm for joint time and phase synchronization in OFDM systems. Paper presented at the 11th IEEE International Symposium on Personal Indoor and Mobile Radio Communications. PIMRC 2000. Proceedings (Cat. No.00TH8525), 819-823. doi:10.1109/PIMRC.2000.881536
