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Pilot Assisted Wireless Transmissions
 IEEE Signal Processing Mag
, 2004
"... The design of pilot assisted wireless transmissions is considered from signal processing and information theoretical perspectives. A general pilot placement model is presented and related figures of merit discussed. A survey of recent pilot assisted transmission theory and techniques is provided. ..."
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Cited by 63 (2 self)
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The design of pilot assisted wireless transmissions is considered from signal processing and information theoretical perspectives. A general pilot placement model is presented and related figures of merit discussed. A survey of recent pilot assisted transmission theory and techniques is provided.
Complementary sequences for ISI channel estimation
 IEEE Transactions on Information Theory
, 2001
"... Abstract—A merit factor based on the sequence autocorrelation function, whose minimization leads to the reduction in the Crámer–Rao lower bound (CRLB) for the variance of “twosided” intersymbol interference (ISI) channel estimation is introduced. Pairs of binary pilot symbol sequences (a preamble ..."
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Cited by 21 (0 self)
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Abstract—A merit factor based on the sequence autocorrelation function, whose minimization leads to the reduction in the Crámer–Rao lower bound (CRLB) for the variance of “twosided” intersymbol interference (ISI) channel estimation is introduced. Pairs of binary pilot symbol sequences (a preamble and a postamble) for channel estimation are jointly designed to minimize this merit factor. Given that the number of channel taps is and the length of a pilot symbol sequence is ( + 1), where, we distinguish between the case when is even and the case when it is odd. For even, we show that complementary sequences not only minimize the merit factor, but also the CRLB. For a subset of odd we construct almostcomplementary periodic sequence pairs that minimize the merit factor. The optimal pilot symbol block signaling requires alternating between two (in most cases) different binary sequences that form the meritminimizing pair. Index Terms—Autocorrelation merit function, complementary sequences, intersymbol interference (ISI) channels, pilot symbols. I.
Training sequence optimization: Comparisons and an alternative criterion
 IEEE Trans. Commun
, 1987
"... ..."
MIMO ISI Channel Estimation Using Uncorrelated Golay Complementary Sets of Polyphase Sequences
"... Abstract — In this paper, optimal training sequence design for multiple input multiple output (MIMO) intersymbol interference (ISI) channels is addressed and several novel lowcomplexity channel estimators are proposed, using uncorrelated Golay complementary sets of polyphase sequences 1. The theore ..."
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Abstract — In this paper, optimal training sequence design for multiple input multiple output (MIMO) intersymbol interference (ISI) channels is addressed and several novel lowcomplexity channel estimators are proposed, using uncorrelated Golay complementary sets of polyphase sequences 1. The theoretical analysis and simulation show that when the additive noise is Gaussian, the proposed best linear unbiased estimator (BLUE) achieves the minimum possible classical CramérRao lower bound (CRLB), if the channel coefficients are regarded as unknown deterministics. On the other hand, the proposed linear minimum mean square error (LMMSE) estimator attains the minimum possible Bayesian CRLB, when the underlying channel coefficients are Gaussian and independent of the additive Gaussian noise. The proposed channel estimators not only achieve the best estimation performance, but also can be implemented with low complexity, via DSP or ASIC/FPGA. This has been possible due to the special structures intrinsic to uncorrelated Golay complementary sets of polyphase sequences, which makes the proposed channel estimators ready to use in the practical MIMO systems.
Wireline Channel Estimation And Equalization
, 2000
"... Communication involves the transmission of information from one point to another through a series of processes. The three basic elements in each... ..."
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Cited by 3 (0 self)
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Communication involves the transmission of information from one point to another through a series of processes. The three basic elements in each...
Designing training sequences for carrier frequency estimation in frequencyselective channels
 IEEE Transactions on Vehicular Technology
, 2006
"... Abstract—A procedure for selecting a training sequence (TS) is developed for frequency estimation in frequencyselective channels. An expression for the unconditional Cramér–Rao bound (UCRB) is obtained by averaging the CRB for frequency estimation over the probability density function of Gaussian ..."
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Cited by 2 (0 self)
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Abstract—A procedure for selecting a training sequence (TS) is developed for frequency estimation in frequencyselective channels. An expression for the unconditional Cramér–Rao bound (UCRB) is obtained by averaging the CRB for frequency estimation over the probability density function of Gaussian random channels. In addition, a necessary and sufficient condition for minimizing the UCRB is derived. Based on these results, a procedure for selecting a TS is developed. Through a computer search, binary TSs up to length 24 are found and tabulated. It is observed that periodic TSs tend to be selected when the TS length is twice the channel duration. Simulation results demonstrate that the proposed TSs can enhance the performance of the maximum likelihood (ML) frequency estimate. Index Terms—Frequency estimation, frequencyselective channels, training sequence (TS) design. I.
Efficient Computation of tr{TR^1} for Toeplitz Matrices
"... An efficient algorithm for the computation of tr{TR^1}, where T and R are Toeplitz matrices and R is also symmetric positive definite, is presented. The method exploits the fact that the trace of TR^1 depends only on the sum of the diagonals of R^1, and not on the whole matrix R^1. To obtain thi ..."
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An efficient algorithm for the computation of tr{TR^1}, where T and R are Toeplitz matrices and R is also symmetric positive definite, is presented. The method exploits the fact that the trace of TR^1 depends only on the sum of the diagonals of R^1, and not on the whole matrix R^1. To obtain this sum, a fast efficient technique, built upon the Trench algorithm for computing the inverse of a Toeplitz matrix, is developed. The complexity of the algorithm depends on the generation function of matrix R and is O(N ln N) for generic functions and O(p ln p) for AR(p) functions.
Efficient computation of tr{TR^1}for Toeplitz Matrices
, 2002
"... An efficient algorithm for the computation of ..."
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"... The codes that combine Channel Estimation and Error Protection (CEEP codes) have received general attention recently, and have been considered a promising methodology to compensate fastvarying fading. It has been shown by simulations that such code design can considerably improve the system perform ..."
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The codes that combine Channel Estimation and Error Protection (CEEP codes) have received general attention recently, and have been considered a promising methodology to compensate fastvarying fading. It has been shown by simulations that such code design can considerably improve the system performance over the conventional separate design under the same code rate. Nevertheless, the major obstacle that prevents from the practice of CEEP codes is that the current codes are all searched by computers, and have no good structure for efficient decoding. Hence, the timeconsuming exhaustive decoding becomes the only way to decode the CEEP codes, and the decoding complexity increases exponentially with the codeword length. In this year, by optimizing the signaltonoise ratio, we found a systematical construction for CEEP codes, and confirmed their equivalence in performance to the computersearched CEEP codes by simulations. Moreover, the structural CEEP codes that we construct by rules can now be maximumlikelihoodly decoded in terms of a newly derived recursive metric for use of the sequential decoding algorithm. Thus, the decoding complexity reduces significantly when being