A conjugate augmented approach to direction-of-arrival estimation

Zhang, Shan; Yum, T.-S.P.

doi:10.1109/tsp.2005.857012

Cited by 42 publications

(33 citation statements)

References 10 publications

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“…According to matrix theory, the updated covariance matrix R has the same noise subspace as R x (i.e., U n = V n ), but provides more accurate estimation on noise subspace [26]. Leveraging the orthogonality between signal subspace and noise subspaces, the frequency of X(t) is obtained through searching for f that maximizes the objective estimator function as follows:…”

Section: Enhanced Music-based Demodulation Schemementioning

confidence: 99%

Uber-in-light: Unobtrusive visible light communication leveraging complementary color channel

Izz

Liu

et al. 2016

IEEE INFOCOM 2016 - The 35th Annual IEEE International Conference on Computer Communications

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Abstract-Recently, Visible Light Communication (VLC) over a screen-camera channel has drawn considerable attention to unobtrusive design. It overcomes the distractive nature of traditional coded image approaches (e.g., barcodes). Previous unobtrusive methods fall into two categories: 1) utilizing alpha channel, a well known concept in computer graphics, to encode bits into the pixel translucency change with off-the-shelf smart devices; and 2) leveraging the spatial-temporal flicker-fusion property of human vision system with the fast frame rate of modern displays. However, these approaches heavily rely on high-end devices to achieve both unobtrusive and high accuracy screen-camera-based data communication without affecting video-viewing experience. Unlike previous approaches, we propose Uber-in-light, a novel unobtrusive and accurate VLC system, that enables real-time screen-camera communication, applicable to any screen and camera. The proposed system encodes the data as complementary intensity changes over Red, Green, and Blue (RGB) color channels that could be successfully decoded by camera while leaving the human visual perception unaffected. We design a MFSK modulation scheme with dedicated frame synchronization signal embedded in an orthogonal color channel to achieve high throughput. Furthermore, together with the complementary color intensity, an enhanced MUSIC-based demodulation scheme is developed to ensure highly accurate data transmission. Our user experience experiments confirmed the effectiveness of delivering unobtrusive data across different types of video content and resolutions. Extensive real-time performance evaluations are conducted using our prototype implementation to demonstrate the efficiency and reliability of the proposed system under diverse wireless environments.

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Section: Enhanced Music-based Demodulation Schemementioning

confidence: 99%

Uber-in-light: Unobtrusive visible light communication leveraging complementary color channel

Izz

Liu

et al. 2016

IEEE INFOCOM 2016 - The 35th Annual IEEE International Conference on Computer Communications

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“…Under MATLA B software environ ment, some parameters are set as: number of antenna cell is M=8, number of signal source is L=3, incidence angles are separately 30, 45 and 60 degree, three incidence signals are 1 For comparison, continuous curve in figure 3 is spatial spectrum drawn by MUSIC method.. Easily being seen, in the case of low SNR, estimation value by LS -ICA can be collected near real value, wh ich will be nearer to real value when SNR increases.…”

Section: Simulation Experimentsmentioning

confidence: 99%

“…Array signal processing, which is one data processing method by array antenna sampling space signals, has become one important branch of signal processing, applied in commun ication, radar, earthquake detection and so on [1] .…”

Section: Introductionmentioning

confidence: 99%

Study on New DOA Estimation Method based-on ULA Under Gaussian Noise

De-zhi¹,

Chen²,

Wang³

et al. 2013

Proceedings of 3rd International Conference on Multimedia Technology(ICMT-13)

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Abstract:The DOA (Direction of Arrival) estimation problem ULA (uniform linear array) was studied, and one new LS-ICA method was proposed based on ULA (uniform linear array) under Gaussian noise, which was filtered during signals separation by ICA. With strict mathematic reasoning, steps of the new DOA estimation method were given. The simulation results showed that the proposed method was more superior to one of MUSIC (M ultiple Signal Classification), especially in degree distinguishing capacity and short data length aspects. In the case of simulation parameters of paper, it was 4 times than M USIC method in degree distinguishing capacity and one tenth in effective data length, which proved method of LS-ICA for DOA estimation was feasible and reliable. Also it provided one new thought for array signals processing and DOA problem.Key words: DOA estimation; LS-ICA; degree distinguishing capacity ; MUSIC 1.IntroductionArray signal processing, which is one data processing method by array antenna sampling space signals, has become one important branch of signal processing, applied in commun ication, radar, earthquake detection and so on [1] .As one of important questions of array signal processing, DOA estimation of space signals plays a role in target orientation and tracking [2] . Among DOA estimation methods, traditional ones, such as Multiple Signal Classification, Estimation of Signal Parameters via Rotational Invariance Technique [3] , usually make use of orthogonal characteristic between signal subspace and noise subspace. In MUSIC method, degree distinguishing capacity is influenced by data length, which confines the improvement of time efficiency. Due to its poor performance to coherent source signals, there are some imp roved MUSIC methods [4] , blind source separation (BSS) method based on genetic algorithm [5] by use of smoothness thinking, improving time efficiency as well as adding computing. In addition, most methods searches the whole space area so that computing is huge, thus, literature [6] co mbines MUSIC with FFT (Fast Fourier Transform), which reduces space searching range.On the basis of s mart array factor use, the paper solves the DOA problem by co mbin ing ICA with LS way marked as LS-ICA in short 1 . 2.Model and basic algorithm of received array signalIn ULA, there are M array cells, distance of near array cells is d. Assume that incident signal is S(t) with an angle of incidence of  , distance between signal source and array antenna is more than d, thus incident signal is thought as surface wave when it enters antenna array. Take array antenna 1 as reference cell (figure 1), suppose received signal in this antenna is 1 ( ) ( ) x t s t  , then received signal in cell 2 is [7] : Simp ly, input array signal vector could be described as:

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“…A number of AOA estimation methods can be used, including MUSIC [21], ESPRIT [22], CA-MUSIC [23] etc. In this paper, we choose MUSIC for its simplicity.…”

Section: Aoa Estimationmentioning

confidence: 99%

Precise Localization with Smart Antennas in Ad-Hoc Networks

Zhang

Yum

2007

IEEE GLOBECOM 2007-2007 IEEE Global Telecommunications Conference

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Abstract-In this paper, we study precise localization using Angle of Arrival (AOA) estimations by smart-antenna equipped beacons in Ad-Hoc networks. The node to be localized sends a signal to its surrounding beacons. The beacons estimate the signal directions with high resolution AOA methods and feed them back to the node for position calculation. In other words, position calculation is not required at beacons. When AOA estimates from three or more beacons are received, ambiguity occurs. Three resolution methods, namely (a) simple averaging (b) Minimax and (c) Precision-weighted averaging are proposed and compared. As estimation bias is heavily dependent on antenna orientations the center-facing approach is found to give better performance in a square field.

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A conjugate augmented approach to direction-of-arrival estimation

Cited by 42 publications

References 10 publications

Uber-in-light: Unobtrusive visible light communication leveraging complementary color channel

Uber-in-light: Unobtrusive visible light communication leveraging complementary color channel

Study on New DOA Estimation Method based-on ULA Under Gaussian Noise

Precise Localization with Smart Antennas in Ad-Hoc Networks

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