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The Delay-Multiply-And-Sum (DMAS) beamformer has recently been presented in the context of medical ultrasound image formation. Images obtained with the DMAS beamformer present improved contrast resolution and noise rejection when compared to images obtained with the standard Delay-And-Sum (DAS) beamformer. We study here the signal statistics for a homogeneous medium using both the DAS and DMAS beamformers...
In cognitive radio networks, multichannel spectrum sensing yield accurate results compared to single channel sensing schemes. However, often realistic correlation among multiple sensing channels is ignored. In this paper, we investigate the performance of a cognitive radio spectrum sensing systems considering more realistic exponential correlation among multiple sensing channels. Closed-form expressions...
The assumption of additive white Gaussian noise (AWGN) to model measurement is not valid since many applications such as in RF power measurement the noise is colored with 1/f spectrum characteristics. With this characteristics, the assumption of independently identically distribution (IID) used in signal detection and estimation becomes not valid. The autocorrelation function and power spectrum can...
A compensation-based user scheduling (CBUS) for multiuser multi-input multi-output (MU-MIMO) systems with delayed feedback channel state information (CSI) is proposed. To cope with the great performance degradation caused by imperfect CSI in the selective transmission/ selective combining (ST/SC) transceiving systems, we propose the CBUS algorithm, which can effectively alleviate the effect of time...
The preamble is one of the indispensable signals in order to discriminate the desired signal from the others. The pseudo-noise (PN) sequences can be used as a part of preamble because of its outstanding correlation properties. One of good preamble detection algorithms for PN sequence is an improved composite pseudo-noise correlation (ICPC) method. In this paper, we focus on the analysis of the probability...
In this work, we analyse the performance of Cognitive Radio Spectrum Sensing (CRSS) systems with multiple receiving antennas considering the effect of correlation among fading branches. Exact closed-form expressions for the average detection probabilities (P̅D) are derived employing Probability Density Functions (PDF) approach for n.i.i.d.-L number of diversity branches over Nakagami-m fading channels...
Article deals with synthesis and analysis of detector of fractal signal at the background of non-correlated Gaussian noise. Model of signal is fractional Brownian motion (fBm), which describes many types of signal particularly flicker-noise. Expression for likelihood ratio is given being based on fBm models in time and spectral fields. This expression is a sufficient statistics for many problems of...
This paper addresses the problem of rate selection for the cooperative hybrid automatic repeat request with chase combination (HARQ-CC) system, where time correlated Nakagami-m fading channels are considered. To deal with this problem, the closed-form cumulative distribution function (CDF) for the combine SNRs through maximal ratio combining (MRC) is first derived as a generalized Fox's H̄ function...
In the view of the appropriateness of the K fading channels for characterizing the wireless communication links, this paper inspects the outage probability and corresponding capacity of such a composite channel model. Differing from the traditional outage definition, we consider the time correlation to describe the real outage occurrences in the mobile network deployments. For more, the fade duration...
In this paper we deal with the performance prediction of the incoherent radar receiver in the presence of arbitrary correlated, possibly non-identically distributed target backscattered echoes. The problem is of interest in some common scenarios accounting for frequency agility, polarization as well as spatial diversity. We develop analytic expressions for the detection probability in terms of power...
In this paper, we propose a reduced-complexity modulation classifier using multi-cycle features extracted from the Spectral Correlation Function (SCF) in order to distinguish among QAM, BPSK, MSK and AM modulation schemes. We analytically derive SCF statistics of the noise and signal features used for classification for finite number of samples, and use Chebyshev inequality to upper bound the minimum...
Novel single integral representations for the multivariate probability density function (PDF) and cumulative distribution function (CDF) of Gaussian class Weibull distributions are derived. A special linear transformation of independent Gaussian random variables is used to generate correlated Weibull random variables. The solutions are expressed in terms of familiar functions which are available in...
In the process of signal acquisition for satellite navigation receiver, compare to the non-coherent acquisition algorithm, the differential correlation based acquisition algorithm is better for improving SNR. Due to the high bit rate of navigation message on P-code, traditional differentially coherent integration algorithm can't be used, a new method called bit-synchronization-based differentially...
Outage probability of a selection combiner (SC) receiver is analyzed over exponentially correlated composite Weibull-gamma fading channels. An expression for the joint probability density function (PDF) of multivariate, exponentially correlated Weibull-gamma distributed random variable is obtained. Using this joint PDF, we derive an expression for the outage probability of a SC receiver with arbitrary...
Performance of a dual maximal ratio combining receiver has been analysed over correlated Hoyt fading channels with non-identical fading parameters. Analytical expressions for the probability density function of the receiver output signal-to-noise ratio (SNR), outage probability and average bit error rate performance for binary, coherent and non-coherent modulations have been presented. Numerical and...
SNR estimation of LFM signal detection is often applied in radar, mobile communications, Radiolocation and seismic exploration with vibrator. The common method of LFM signal detection is correlation, which can not only be used to explain time delay in Multipath Propagation, but also to estimate SNR in detection of output signal. The records of signal plus noise before the signal detection are called...
A novel algorithm for Signal-power-to-Noise-power ratio (SNR) estimation in AWGN channel is proposed in this paper. The relationship between SNR and the distribution of instantaneous phase (DIP) of BPSK signal is investigated, and the SNR estimator is constructed according to this relationship. Correlation coefficients are used to judge the similarity of the DIP between the theoretical one and the...
In this contribution, we investigate the impact of channel correlation on the ergodic capacity, capacity statistics and symbol error rate (SER) for maximal ratio combiner (MRC) multichannel diversity systems over correlated Rayleigh fading channels. We derive exact closed-form expressions for average channel capacity, an upper bound and its asymptotically tight approximation. The capacity statistics...
We propose a data hiding algorithm for stereo audio signals which embeds data using the polarity of the reverberations added to the high-frequency channels. We replace the high-frequency components with one middle channel, and embed data as the polarity of reverberations added to each channel in order to adjust the coherence between these channels. Blind detection of embedded data is possible using...
By analytical means, this paper investigates the application of a multi-periodic preamble for the synchronization in OFDM systems, which is based on an auto-correlation of the received signal. In contrast to common system configurations, the multi-periodic preamble enables to select the two parameters correlation shift and correlation window length independently of each other. This allows adapting...
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