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Time-varying voltage patterns have expanded the capabilities of the nanopore instrument for single molecule manipulation and measurement, in research and commercial applications. The ability to apply time-varying voltages enhances the nanopore as a tool for single-molecule biophysical studies, for example, by permitting dynamic force spectroscopy. A challenge with voltage-varying experiments is that...
Analytical methods of signal recovery that are not limited to specific channel conditions are of great importance for an amplify and forward (AF) relay network, as the performance of diversity systems operating over such conditions are affected by various channel characteristics. Signal extraction from a correlated noise environment remains as another crucial issue that requires exploration. A block...
Eigenspace techniques are very popular techniques for blind channel identification, but are ones with a large complexity, cubic in the channel order. The newly introduced channel compaction is a signal processing technique that consists in using small-sized linear transformations to progressively force to zero some of the channel coefficients. As such, channel compaction was used to develop the first...
Orthogonal frequency-division multiplexing (OFDM) wireless communication systems suffer severe inter- channel interference(ICI) due to high Doppler frequency spread, the paper investigate a kind of channel estimation approach that combines the multiply continue OFDM symbols and decision feedback technology. Further, we present a low-complexity algorithm to evaluate the ICI components for decision...
Noise in water is very crtical and may destroy the the OFDM based underwater acoustic communication system. The performance of pilot tones based channel estimation will not be the good choice under low SNRs. Complete frequency response of data channel is usually obtained by interpolating channel frequency response at pilot bits, such that the error of interpolation influences and degrades the performance...
This paper presents a self-adjustment of the length of the channel impulse response using a classical Cholesky Factorization. This is of special importance in the context of algorithms containing a matrix inversion and the rank of this matrix is strongly related to the length of the channel impulse, i.e. interferer cancellation algorithm [1]. When the length of the channel impulse response is overestimated,...
Novel blind and semi-blind subspace channel estimations are proposed for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems in the presence of virtual carriers (VC). Slow convergence rate is a drawback of subspace method in deriving the noise/signal subspaces from the second-order statistics of received signals, especially when the dimension of received...
A coherent cooperative communication system is proposed in which a distributed array of transmit nodes forms a beam at a desired receiver while simultaneously steering nulls at several protected receivers. Coherent transmission is achieved through a receiver-coordinated protocol where the receivers in the system use state-space channel tracking and provide feedback to the transmit cluster to facilitate...
In this paper, we analyze the channel estimation technique for OFDM (orthogonal frequency division multiplexing) used in VLC (Visible Light Communication system). A Post-Processing DFT (Discrete Fourier Transformation) channel estimation method was proposed to improve the system performance by eliminating the noise outside the maximum channel delay. After linear interpolation, the channel estimation...
Consider a system in which the signal is transmitted from the source to the destination via an amplify-and-forward relay. For such a system, we derive in this paper, novel receivers that have complete knowledge of either the source-relay link or the relay-destination link. These receivers are termed as, ‘half-coherent receivers’ as they have channel-state-information (CSI) of only one of two links...
A novel algorithm of iterative channel estimation and turbo decoding for pilot symbol assisted modulation (PSAM) is proposed. The proposed channel estimation is based on least squared fitting (LSF) theorem. Compared with the linear optimum MMSE (minimum mean square error) channel estimation, it doesn¡¦t require any channel characteristic like as fading rate or noise variance. We discuss the effect...
A novel capacity estimator for low rank multiple-input multiple-output (MIMO) channels impaired with white noise is proposed by reducing the impact of noise on both the spatial multiplexing gain and on the power gain. Numerical results show that the estimator performs better than conventional methods in estimation accuracy, and the requirements on the number of observations as well as on the computation...
The state estimation problem is addressed in the paper for a complex dynamical network with stochastic noise in transmission channel. A new scheme based on integral observer approach is proposed for the complex dynamical network to estimate the network's states. It is demonstrated that the proposed scheme is effective under a noisy communication environment by using Lyapunov stability theory. A sufficient...
In this paper, we use an adaptive method for identifying of minimum phase channel parameters. We have selected two channels as the Proakis's ‘B’ channel and the Macchi's channel. We compared this method with those based on the Higher Order Statistics. The obtained simulation results in noisy environment and for different data input channel, demonstrate that the adaptive method is efficient and can...
In the 3rd generation partnership project (3GPP) long term evolution (LTE) time division duplex (TDD) systems, base stations use uplink sounding reference signals (SRSs) to estimate downlink channel state information (CSI) for downlink beamforming transmissions. Because SRSs sent by up to 8 users are multiplexed on the same time-frequency resources, there exist mutual interferences among these SRSs...
In the compressed sensing framework, reconstruction algorithms attempt to recover a signal from a collection of projections on randomly generated vectors. The Matching Pursuit algorithm is a greedy procedure that iteratively selects the current “best” match.
A sensor network's motes observe the environment, make estimates based on observations with spatially correlated noise sources, and then send/relay these estimates to a Cluster-Head (CH). A novel scheme based on dithered quantization and channel compensation is used to ensure that each mote's local estimate received by the CH is unbiased. Based on an upper bound of the noise covariance matrix, the...
In this contribution, channel estimation for OFDM system in high mobility environment with the presence of Gaussian and non-Gaussian impulse noise with different ranges interfering with reference signals is faced. The estimation of the frequency selective time varying multipath fading channel is performed by using a nonlinear channel estimator based on a complex Least Squares Support Vector Machine...
In this paper, we present a robust technique based on cost reference particle filter (CRPF) for combined channel impulse response (CIR) estimation and phase noise (PN) tracking in OFDM systems without any priori information regarding the noise in the state and measurement equation. Contrary to previous works, we hold no assumption regarding the magnitude of the PN variance and hence no approximation...
In this paper novel subspace-based blind schemes are proposed and applied to the sparse channel identification problem. Moreover, adaptive sparse subspace tracking methods are proposed so as to provide efficient real-time implementations. The new algorithms exploit the subspace sparsity either via employing ℓ1-norm relaxation or through greedy-based optimization. The derived schemes have been tested...
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