Computer Science and Information Systems 2012 Volume 9, Issue 4, Pages: 1385-1406
https://doi.org/10.2298/CSIS120303051J
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Cited by
Orthogonal sequences based multi-CFO estimation and semi-blind ICA based equalization for multiuser comp systems
Jiang Yufei (Dept. of Electrical Engineering and Electronics, the University of Liverpool, L GJ Brownlow Hill, Liverpool, U.K. + Dept. of Electrical and Electronic Engineering, Xi’an Jiao Tong Liverpool University, Suzhou, China)
Xu Zhu (Dept. of Electrical Engineering and Electronics, the University of Liverpool, L GJ Brownlow Hill, Liverpool, U.K.)
Lim Enggee (Dept. of Electrical and Electronic Engineering, Xi’an Jiao Tong Liverpool University, Suzhou, China)
Yi Huang (Dept. of Electrical Engineering and Electronics, the University of Liverpool, L GJ Brownlow Hill, Liverpool, U.K.)
We propose a low-complexity carrier frequency offset (CFO) estimation
approach and an independent component analysis (ICA) based semi-blind
equalization structure for the orthogonal frequency division multiplexing
(OFDM) based multiuser coordinated multi-point (CoMP) systems. A group of
orthogonal sequences are employed to enable separation and simultaneous
estimation of multiple CFOs at base stations, dividing a complex
multi-dimensional search into series of low-complexity mono-dimensional
searches. Then, a small number of pilot symbols attached to the source data,
are used to resolve the ambiguity problem in the ICA equalized signals. It
has a low complexity, as the permutation and quadrature ambiguity can be
eliminated simultaneously, rather than sequentially by the previous precoding
aided method. Simulation results show that the proposed semi-blind
equalization structure has a bit error rate (BER) performance close to the
ideal cases of the zero forcing (ZF) and minimum mean square error (MMSE)
based equalization with perfect channel state information (CSI) and no CFO,
and also significantly outperforms the constant amplitude zero
autocorrelation (CAZAC) sequences based CFO estimation method.
Keywords: carrier frequency offset (CFO), coordinated multi-point (CoMP), orthogonal frequency division multiplexing (OFDM), independent component analysis (ICA)