The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A Pulse Recurrence Interval (PRI) estimation algorithm for multicomponent linear frequency modulation (M-LFM) signals transmitted from multiple-input multiple-output (MIMO) radars is proposed in this paper. Firstly, based on single antenna reconnaissance receiver, the signal model of the intercepted M-LFM signals and problems of PRI estimation are analyzed. Then, PRI estimation algorithm is proposed...
The Doppler shift, or equivalently the vehicular speed, represents the fading rate of mobile channels, thus its estimation must be important in the mobile communication system. This paper investigates the estimation of Doppler shift by taking into consideration the rate of minimum (ROM) of envelope, where both the iterative processing and polynomial fitting are employed to improve the estimating performance...
To estimate multiple-input multiple-output (MIMO) channels, invariable step-size normalized least mean square (ISSNLMS) algorithm was applied to adaptive channel estimation (ACE). Since the MIMO channel is often described by sparse channel model due to broadband signal transmission, such sparsity can be exploited by adaptive sparse channel estimation (ASCE) methods using sparse ISS-NLMS algorithms...
In this paper, the main purpose of our algorithm is to solve the two-dimensional estimation problem under the more practical case of circular and non-circular signals coexist. Firstly, taking advantage of non-circularity properties, we extend the received data matrix to augment the maximum number of detectable signals. Secondly, utilizing unitary extended propagator method (UEPM), we obtained a higher...
In this paper, we examine the channel estimation problem for one-way relay network(OWRN) under time-selective fading channel scenario. Our aim is to estimate the individual channels of each relay hop at the destination with unknown data from source. We utilize the relay's aided estimation function through superimposing pilots at relay, adopt the autoregressive (AR) model to characterize the time-varying...
In this paper, we examine the Bayesian Cramér-Rao lower bounds (BCRBs) for channel estimation in an amplify-and-forward (AF) one-way relay network (OWRN) under time selective flat fading scenario, where the superimposed training is adopted at relay node in order to achieve individual channel estimation. We formulate the nonlinear dynamic state space for individual channels and derive online/offline...
Owing to the frequency-selective fading channel with a carrier frequency of OFDM (orthogonal frequency division multiplexing) signal to noise ratio (SNR) estimation problem, we proposed SNR blind estimation method based on air carrier OFDM system. Due to the inconsistency between the oscillator and the received signal, the received signal will be with a certain deviation. The presence of frequency...
In this paper, the Bayesian Cramér-Rao lower bounds (BCRBs) on dynamic individual channel estimation is examined in an amplify-and-forward (AF) one-way relay network (OWRN) under time selective flat fading channel scenario, where the superimposed training framework is adopted. The target of our work is to formulate the nonlinear dynamic state-space equation for individual channels and derive the online/offline...
We combine sound activity detection, sound enhancement, and direction of arrival (DOA) estimation system to an integrated system. We use sound activity detection for finding frames which are sound-dominated, then pass the signal to the subspace based sound enhancement for denoising. Finally, the denoised signal will be input to DOA detection system for sound tracking. The generalized cross-correlation...
In order to solve the problem of existing a large estimation error when using the current algorithm which based on the autocorrelation matrix eigenvalue decomposition to estimate the SNR of the short signal frame in the communication system, this paper proposes an improved blind SNR estimation algorithm. Based on the previous algorithm, it introduces an idea of re-constructing the autocorrelation...
Direct spread spectrum signal with high anti-interference property, It has the characteristics of pseudo noise. Research on direct spread spectrum signal parameter estimation has important practical significance. According to the transmission characteristics of direct spread spectrum signal, using the time domain correlation method to estimate pn code period and using the frequency domain smooth periodogram...
Recently, a proactive estimation method has been proposed to obtain the cross-channel gain from cognitive transmitter (CT) to primary receiver (PR), where CT acts as a full-duplex amplified-and-forward (AF) relay for primary users. However, since the cognitive and primary users usually have no cooperation, it has no guarantee that the direct and relay signals are synchronized, i.e., the time delay...
Mutual coupling is a practical problem in array signal processing, which seriously degrades the performance of most high-resolution array processing methods. In this paper, an improved sparse representation method is proposed for direction-of-arrival estimation in the presence of unknown mutual coupling. By making use of the special structure of mutual coupling matrix for uniform linear array, the...
An accurate direction-of-arrival (DOA) estimation algorithm is proposed with a uniform linear array (ULA) when coherent and uncorrelated signals coexist. By selecting the rank from the covariance matrix of array output, we first reconstruct a Toeplitz matrix so as to achieve the objective of decorrelation similar to reference [2]. And then we proposed a spectrum of improved MUSIC (named as SI-MUSIC)...
Corner detection has shown its great importance in many computer vision tasks. However, in real-world applications, noise in the image strongly affects the performance of corner detectors. Few corner detectors have been designed to be robust to heavy noise by now, partly because the noise could be reduced by a denoising procedure. In this paper, we present a corner detector that could find discriminative...
This paper presents a new methodology based on the reduced rank covariance matrix for direction of arrival (DOA) estimation, which can be have lower complexity compare to the classical Multiple Signal classification (MUSIC). Since the reduced rank covariance matrix contains all the information that the traditional covariance has, the performance of the proposed method is almost the same with the classical...
In order to solve the problem that most of the directions-of-arrival (DOA) algorithms are based on the prior knowledge of source number and the estimation error of source number leads to the degradation of DOA algorithm performance, a conformal array DOA algorithm with unknown source number is proposed. This method is realized by introducing the pseudo expected signal. The optimum weight deduced by...
Representing the reception condition directly, both Signal-to-noise ratio (SNR) and Doppler shift are important parameters in mobile channels, and therefore are widely used in system performance evaluations and adaptive applications. Accordingly, this paper investigates a frequency domain iterative estimator for SNR and Doppler shift in mobile communications, where the discrete cosine transform (DCT)...
In this paper, differential modulation (DM) schemes, including single differential and double differential, are proposed for amplify-and-forward two-way relaying (TWR) networks with unknown channel state information (CSI) and carrier frequency offsets. Most existing work in TWR assumes perfect channel knowledge at all nodes and no carrier offsets. However, accurate CSI can be difficult to obtain for...
In this letter, we research a spatiotemporal-domain-based time–frequency peak filtering (TFPF) method in order to remove the large error (bias) of the conventional TFPF in intermediate-frequency seismic record discrimination. An intermediate-frequency seismic signal is one whose dominant frequency is about 40 Hz or higher. To find a balance between noise attenuation and reflected signal preservation,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.