O.E. Agazzi, Mario R. Hueda, Hugo S. Carrer et al. · 2005
This paper discusses the investigation of max- imum-likelihood sequence estimation (MLSE) receivers operating on intensity-modulated direct-detection optical channels. The study focuses on long-haul or metro links spanning several hun- dred kilometers of single-mode fiber with optical amplifiers. The structure of MLSE-based optical receivers operating in the pres- ence of dispersion and amplified spontaneous emission (ASE), as well as shot and thermal noise, are discussed, and a theory of the error rate of these receivers is developed. Computer simulations show a close agreement between the predictions of the theory and simulation results. Some important implementation issues are also addressed. Optical channels suffer from impairments that set them apart from other channels, and therefore they need a special investigation. Among these impairments are the facts that the optical channel is nonlinear, and noise is often non-Gaussian and signal dependent. For example, in optically amplified single-mode fiber links, the dominant source of noise is ASE noise, which after photodetection is distributed according to a noncentral chi-square probability density function. In addition, optical fibers suffer from chromatic and polarization-mode dispersion (PMD). Although the use of MLSE in optical channels has been discussed in previous literature, no detailed analysis of optical receivers using this tech- nique has been reported so far. This motivates the study reported in this paper. Index Terms—Channel estimation, chromatic dispersion, elec- tronic dispersion compensation (EDC), equalization, maximum- likelihood sequence estimation (MLSE), non-Gaussian noise, po- larization-mode dispersion (PMD).
Cited by 7
Bernd‐Peter Paris · 2002
Many problems in digital communications can be modeled by means of a discrete-time finite-state Markov process representing the signal which is observed in independent identically distributed noise. If the parameters of the process are known, the problem is well understood and the optimum solution to the problem is to determine the state sequence which is most likely in light of the received data. This approach is referred to as maximum likelihood sequence estimation (MLSE) and can be performed computationally efficiently using the Viterbi algorithm. The present authors consider the important case when some or all of the process parameters are unknown. The traditional approach to this problem involves embedding a known "training sequence" in the data and estimating the parameters from the resulting received signal. Then, the data are extracted using the estimated parameters. In contrast, the authors propose to exploit the structure and finiteness of the state space of the signal to determine the most likely state sequence without resorting to a known training sequence. They refer to this approach as self-adaptive MLSE.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cited by 2
Robert J. Elliott, J.B. Moore, Subhrakanti Dey · IEEE Transactions on Circuits and Systems I Fundamental Theory and Applications · 1996
In this brief, we consider risk-sensitive Maximum Likelihood sequence estimation for hidden Markov models with finite-discrete states. An algorithm is proposed which is essentially a risk-sensitive variation of the Viterbi algorithm. Simulation studies show that the risk-sensitive algorithm is more robust to uncertainties in the transition probability matrix of the Markov chain. Similar estimation results are also obtained for continuous-range state models.
Cited by 6
Krzysztof Wesołowski · IFAC Proceedings Volumes · 1992
Cited by 2
Krzysztof Wesołowski · Elsevier eBooks · 1993
Cited by 0
CUHK Digital Repository (Chinese University of Hong Kong) · 1991
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Huang, Yinggan · PRISM (University of Calgary) · 2009
Cited by 0Open access
Wai Ho Mow · IEEE Transactions on Information Theory · 1994
Considers the problem of data detection in multilevel lattice-type modulation systems in the presence of intersymbol interference and additive white Gaussian noise. The conventional maximum likelihood sequence estimator using the Viterbi algorithm has a time complexity of O(m/sup /spl nu/+1/) operations per symbol and a space complexity of O(/spl delta/m/sup /spl nu//) storage elements, where m is the size of input alphabet, /spl nu/ is the length of channel memory, and /spl delta/ is the truncation depth. By revising the truncation scheme and viewing the channel as a linear transform, the authors identify the problem of maximum likelihood sequence estimation with that of finding the nearest lattice point. From this lattice viewpoint, the lattice sequence estimator for PAM systems is developed, which has the following desired properties: 1) its expected time-complexity grows as /spl delta//sup 2/ as SNR/spl rarr//spl infin/; 2) its space complexity grow as /spl delta/; and 3) its error performance is effectively optimal for sufficiently large m. A tight upper bound on the symbol error probability of the new estimator is derived, and is confirmed by the simulation results of an example channel. It turns out that the estimator is effectively optimal for m/spl ges/4 and the loss in signal-to-noise ratio is less than 0.5 dB even for m=2. Finally, limitations of the proposed estimator are also discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cited by 91
XU Pei-xia · 2008
A novel algorithm for adaptive reduced-complexity blind maximum likelihood sequence estimation(MLSE) is proposed.Basic idea behind the proposed algorithm is the principle of per-survivor processing(PSP) and the adaptive selection of survivor path.The key feature of the proposed algorithm is that the minimum Euclidean distance in the trellis can adaptively be estimated,and then only a small number of the most likely survivors in the trellis are retained and utilized for joint channel and data estimation.Theoretical analysis and computer simulation results show that,for channels with severe intersymbol interference(ISI),the proposed algorithm has higher performance in symbol error rate and lower computational complexity at high signal-to-noise ratios(SNR).
Cited by 0
Behrouz Farhang‐Boroujeny · National University of Singapore · 1995
IEEE Communication Theory Mini-Conference, Proceedings, CTMC
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Xu Jin Biao, Du Min · 2002
This paper presents a new reduced-state, decision feedback Viterbi equalizer (RSSDF-PSP) which works blind. In the RSSDF-PSP, the whole length of the channel impulse response (CIR) is divided into two parts. The first part is handled by the MLSE and the second part is handled by a soft decision feedback filter. The first part channel estimate was obtained by the blind per-surviving processing (PSP) algorithm, the second part channel estimate was obtained by the decision feedback filter. The complexity of the MLSE is significantly reduced by the second part CIR truncation. Simulation results show the RSSDF-PSP has nearly the same performance as the MLSE. It provides the best tradeoff between complexity and performance of MLSE.
Cited by 1
Shu‐Chen Ho, K.S. Chung, A. Pinnock · 2005
In the reception of Generalized Tamed Frequency Modulation (GTFM) signals corrupted by noise, Maximum Likelihood Sequence Estimation (MLSE) technique has been successfully used to minimize the bit error rate. In this paper, we review the MLSE in the context of GTFM, and report its imple-menation in VLSI 2 micron CMOS technology. Testability issues in the IC design are discussed.
Cited by 0
D.D. Falconer, F. Magee · Bell System Technical Journal · 1973
Maximum likelihood data sequence estimation, implemented by a dynamic programming algorithm known as the Viterbi algorithm (VA), is of considerable interest for data transmission in the presence of severe intersymbol interference and additive Gaussian noise. Unfortunately, the required number of receiver operations per data symbol is an exponential function of the duration of the channel impulse response, resulting in unacceptably large receiver complexity for high-speed PAM data transmission on many channels. We propose a linear prefilter to force the overall impulse response of the channel/prefilter combination to approximate a desired truncated impulse response (DIR) of acceptably short duration. Given the duration of the DIR, the prefilter parameters and the DIR itself can be optimized adaptively to minimize the mean-square error between the output of the prefilter and the desired prefilter output, while constraining the energy in the DIR to be fixed. In this work we show that the minimum mean-square error can be expressed as the minimum eigenvalue of a certain channel-dependent matrix, and that the corresponding eigenvector represents the optimum DIR. An adaptive algorithm is developed and successfully tested. The simulations also show that the prefiltering scheme, used together with the VA for two different channel models, compares favorably in performance with another recently proposed prefiltering scheme. Limiting results for the case where the prefilter is considered to be of infinite length are obtained; it is shown that the optimum DIR of length two must be one of two possible impulse responses related to the duobinary impulse response. Finally we obtain limiting results for the case where the transmitting filter is optimized.
Cited by 396
Wong, Cheung · MacSphere (McMaster University) · 1980
This thesis is missing page 155, the other copies of the thesis are also missing this page. -Digitization Centre
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T. Foggi, G. Colavolpe, FORESTIERI, Enrico et al. · CINECA IRIS Institutional Research Information System (Sant'Anna School of Advanced Studies) · 2006
A method of and a receiver for detection of a received signal in an optical fibre communication system using Viterbi algorithm methodology in which branch metrics are obtained using approximated expressions to calculate the branch metrics. Use of the expressions results in practically the same performance as a receiver based on exact metrics.
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Hiroshi Kubo, K. Murakami, Tadashi Fujino · IEEE Transactions on Communications · 1999
This paper compares the following two maximum likelihood sequence estimation schemes incorporating carrier phase estimation for coded MPSK: (1) the respective-state channel estimation and (2) the multiple differential detection. This paper confirms by analysis and computer simulation that both schemes have similar performance in the absence of intersymbol interference.
Cited by 3
Bernd‐Peter Paris, Adnan Shah · 2002
The problem of implementing self-adaptive equalization algorithms in real-time is addressed. Self-adaptive equalization determines the transmitted sequence without using a training sequence. We focus our attention on the special case of a discrete-time finite-state Markov process in which a sequence of equally likely symbols s/sub k/ drawn from an a discrete and finite alphabet A is input to a channel which introduces intersymbol interference in addition to white Gaussian noise. Simulation results for the self-adaptive tree search procedures based on Fano (1963), stack and M-algorithm are presented.
Cited by 0
Slimane Ben Slimane · 1992
Constant-envelope Quadrature Pulse-Overlapping Modulated (QPOM) signals have good spectral properties suitable to applications using nonlinear or saturated power amplifiers. In this thesis we present a Maximum Likelihood Sequence Estimation (MLSE) receiver structure for QPOM signals and analyze its performance in both Additive White Gaussian Noise (AWGN) and fading channels. The quadrature pulse-overlapping modulator is first decomposed into a linear encoder followed by a memoryless modulator. The trellis diagram representing this inherent non-redundant coding structure is then used to construct its MLSE receiver. The upper bounds on the average bit error probability in both AWGN and Rayleigh fading channels are derived. Computer simulations are also used to verify the analytical results. Performance of the introduced scheme in fast fading, shadowed mobile satellite channels is also studied. Results show that this scheme outperforms conventional QPSK techniques in fading channels. While maintaining a low constellation density of 4PSK, its performance is comparable to those of 4-state 8PSK Trellis Coded Modulation (TCM) schemes. The performance of QPOM signals over fading channels can be further improved using some extra redundancy. Based on the new representation of the QPOM scheme, an external convolutional code is combined with the QPOM memory and considered as one entity to be optimized. This optimization is achieved by maximizing the minimum length of the shortest error event path through the trellis diagram of the equivalent code as well as the product of the squared branch distances along that error event path. The obtained structure is then applied to M-ary QPOM signals. The constant envelope, compact spectrum, superior performance, and low complexity make the QPOM scheme a good choice for portable/mobile satellite communications to achieve the requirements of low cost, small size, and high power and bandwidth efficiencies
Cited by 0
Ben Slimane, Slimane · Spectrum Research Repository (Concordia University) · 1992
Constant-envelope Quadrature Pulse-Overlapping Modulated (QPOM) signals have good spectral properties suitable to applications using nonlinear or saturated power amplifiers. In this thesis we present a Maximum Likelihood Sequence Estimation (MLSE) receiver structure for QPOM signals and analyze its performance in both Additive White Gaussian Noise (AWGN) and fading channels. The quadrature pulse-overlapping modulator is first decomposed into a linear encoder followed by a memoryless modulator. The trellis diagram representing this inherent non-redundant coding structure is then used to construct its MLSE receiver. The upper bounds on the average bit error probability in both AWGN and Rayleigh fading channels are derived. Computer simulations are also used to verify the analytical results. Performance of the introduced scheme in fast fading, shadowed mobile satellite channels is also studied. Results show that this scheme outperforms conventional QPSK techniques in fading channels. While maintaining a low constellation density of 4PSK, its performance is comparable to those of 4-state 8PSK Trellis Coded Modulation (TCM) schemes. The performance of QPOM signals over fading channels can be further improved using some extra redundancy. Based on the new representation of the QPOM scheme, an external convolutional code is combined with the QPOM memory and considered as one entity to be optimized. This optimization is achieved by maximizing the minimum length of the shortest error event path through the trellis diagram of the equivalent code as well as the product of the squared branch distances along that error event path. The obtained structure is then applied to M-ary QPOM signals. The constant envelope, compact spectrum, superior performance, and low complexity make the QPOM scheme a good choice for portable/mobile satellite communications to achieve the requirements of low cost, small size, and high power and bandwidth efficiencies
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Hidekazu Murata, Susumu Yoshida · 2002
TDMA data transmission is used in various radio communication systems. Receivers for TDMA systems require the estimation of some parameters. In the system considered, the delay profile is acquired at the beginning of each burst, while the frequency offset between modulation and demodulation is tracked from burst to burst. A joint frequency offset and delay profile estimation technique for maximum-likelihood sequence estimation is proposed. In this algorithm, the frequency offset is simultaneously estimated during the delay profile estimation using the residual error of the delay profile estimation. Computer simulations have been performed to demonstrate the performance of the proposed algorithm. It is shown that the allowable frequency offset range of the proposed receiver is over 10 times as large as that of the conventional receiver without frequency offset compensator.
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