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ABSTRACT: Wireless communication systems such as global system for mobile
(GSM) communications are playing a growing role for data transmission.
In order to ensure reliable transmission, the channel impulse response
has to be estimated accurately. This is a difficult task particularly
for fast fading channels caused by high-speed mobile units. We deal with
the application of nonblind and blind channel estimation approaches to
identify the full rate data Traffic CHannel (TCHF9.6) of GSM. We present
a new iterative channel estimation scheme leading to a significant
performance improvement especially for high-speed propagation with
Doppler frequencies up to 500 Hz. Furthermore, it is shown that blind
channel estimation schemes could be as efficient as nonblind methods
when regarding bit error rates (BERs) after channel decoding in terms of
the E¯<sub>b</sub>/N<sub>0</sub> ratio. Moreover, a solution for
the scalar ambiguity inherent in all blind estimation approaches is
suggested
IEEE Journal on Selected Areas in Communications 10/2001; · 3.41 Impact Factor
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ABSTRACT: Finite-alphabet-based blind channel estimation in OFDM systems is known to be extremely complex due to an exhaustive search to be performed over a tremendous number of channel coefficient combinations. In, this paper, we present a novel blind channel estimator which dramatically reduces this number of coefficient combinations to be checked without a significant deterioration in estimation quality. Hence, the new low complexity approach enables the application of blind channel estimators based on the finite alphabet set even if the transmitted data are high-rate modulated. Furthermore, we show that the performance of blind channel estimation can be improved by an iterative process based upon the capabilities of channel coding. Using bit error rates, the algorithm is tested with simulations and compared to other blind and nonblind channel estimators.
Signals, Systems and Computers, 2001. Conference Record of the Thirty-Fifth Asilomar Conference on; 02/2001
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ABSTRACT: Channel estimation plays a leading role in wireless communication
systems such as GSM (Global System for Mobile communications). Putting
the main emphasis on investigating the application of non-blind and
blind channel estimation approaches to the identification of a full rate
data Traffic CHannel (TCH/F9.6), we present a new idea of an iterative
channel estimation based upon the capabilities of channel coding. We
show that this method leads to a significantly improved performance
especially for high speed propagations with Doppler frequencies up to
500 Hz. Giving the bit error rates (BERs) before and after channel
decoding in terms of the E¯<sub>b</sub>/N<sub>0</sub> ratio, we
show, furthermore, that blind channel estimation schemes could be as
efficient as non-blind methods
Personal, Indoor and Mobile Radio Communications, 2000. PIMRC 2000. The 11th IEEE International Symposium on; 02/2000
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ABSTRACT: Due to the solution of an eigenvalue problem, a common drawback of
all blind estimation algorithms is the interference of the estimated
channel impulse response caused by an unknown complex factor. Since
maximum likelihood sequence estimation (MLSE) requires the knowledge of
the exact channel characteristics, we present in this paper a method
based on a linear mean square error (MSE) solution which enables the
estimation of this factor using a-priori information of the source
signal. On the assumption of COST-207 mobile radio channels, we compare
the blind channel estimation approaches with the non-blind
cross-correlation method (CC) used in state-of-the-art GSM receivers
(Global System for Mobile communications) and give the bit error rates
(BER) after Viterbi detection in terms of the signal-to-noise ratio
(SNR). Finally, we also study the influence of non-Gaussian co-channel
interference (CCI) on the blind and non-blind estimation schemes
Higher-Order Statistics, 1999. Proceedings of the IEEE Signal Processing Workshop on; 02/1999
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ABSTRACT: As a fundamental component of the global system for mobile
communications (GSM), channel coding aims at improving speech and data
transmission quality when the signal encounters disturbances. We put the
main emphasis on investigating the application of blind channel
estimation approaches based on second order statistics and/or higher
order statistics to the identification of a full rate data traffic
channel (TCH/F9.6). Giving the bit error rates after equalization and
channel decoding in terms of the E¯<sub>b</sub>/N<sub>0</sub>
ratio, we show that there are blind channel estimation algorithms which
are almost as efficient as non-blind methods even if the disturbance is
non-Gaussian
Decision and Control, 1999. Proceedings of the 38th IEEE Conference on; 02/1999
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ABSTRACT: We compare the effect of blind and nonblind channel estimates on
the performance of Global System for Mobile communications (GSM)
receivers. More precisely, we investigate whether two blind approaches,
based on higher order statistics (HOS), can compete with two
conventional methods, exploiting training sequences. For blind and
nonblind estimates of six fast and slowly fading mobile radio channels,
we give simulated bit error rates (BERs), after Viterbi detection, in
terms of the signal-to-noise ratio (SNR). We also study the influence of
cochannel interferers at different values of the signal-to-interference
ratio (SIR). Averaged over the six channel examples, we demonstrate that
the blind channel estimation algorithm eigenvector approach to blind
identification (EVI) leads to an SNR loss of 1.2-1.3 dB only, while it
saves the 22% overhead in GSM data rate caused by the transmission of
training sequences. Since just 142 samples are used for blind channel
estimation, we consider this performance outstanding for an approach
based on HOS
IEEE Journal on Selected Areas in Communications 11/1998; · 3.41 Impact Factor
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ABSTRACT: We investigate in this paper whether the HOS-based blind channel
estimation method EVI (eigenvector approach to blind identification) can
compete with the nonblind cross-correlation-based scheme used in
state-of-the-art GSM receivers (Global System for Mobile communication).
For blind, non-blind, and ideal estimates of COST-207 mobile radio
channels, we give simulated bit error rates (BER) after Viterbi
detection in terms of the mean signal-to-noise ratio (SNR). Averaged
over three COST-207 propagation environments, EVI leads to a mean SNR
loss of 1.2 dB only, while it saves the 22% overhead in the GSM data
rate due to the transmission of training sequences. Since just 142
samples are used for channel estimation, we consider this performance
outstanding for an approach based on HOS
Higher-Order Statistics, 1997. Proceedings of the IEEE Signal Processing Workshop on; 08/1997
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http://www.ant.uni-bremen.de/pub/papers/pvkb01_paper.pdf.
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http://www.ant.uni-bremen.de/pub/papers/kpv01_paper.pdf.
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http://www.ant.uni-bremen.de/pub/papers/pk99_paper.ps.gz.
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http://www.ant.uni-bremen.de/pub/papers/pkk00_paper.pdf.
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http://www.ant.uni-bremen.de/pub/papers/pk00_paper.pdf.
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http://www.ant.uni-bremen.de/pub/papers/pk99a_paper.pdf.
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http://www.ant.uni-bremen.de/pub/papers/pvk01_paper.pdf.
