On estimating the noise power in array processing

² Automatic beamforming for noncircular signals with distinct noncircularity-rates can be achieved via Takagi factorization based on the second-order statistics. However, the requirement on noncircularity-rate diversity can not be satisfied by rectilinear signals (e.g., AM and BPSK signals), which are used in many practical communications systems. A mixed-order Takagi factorization scheme is herein proposed to handle coexisted rectilinear signals, wherein the fourth-order statistics is used for adjusting virtually the noncircularity-rates of signals, while the second-order statistics is utilized for blind identification. Numerical examples are also included to illustrate the performance of the proposed beamformer.Keywords ² Array signal processing, adaptive arrays, beamforming

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“…We assume in this paper that 2 n 2 n is known or already estimated in advance using, for instance, the method in [21]. In the sequel, we denote…”

Section: Problem Formulationmentioning

confidence: 99%

Blind beamforming for rectilinear signals

Liu

Yuan

et al. 2011

2011 4th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications

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“…The noise power σ n 2 used for constructing O v 1 v 1 can be estimated a priori by physical measurement or by numerical techniques (Stoica, 1992). A popular technique is to compute the eigenvalues of R v 1 v 1 and identify those "smallest" eigenvalues.…”

Section: Signal Subspace-based Estimationmentioning

confidence: 99%

Subspace‐based techniques for 2‐d DOA estimation with uniform circular array under local scattering

Chang¹,

Jen

2006

Journal of the Chinese Institute of Engineers

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In mobile communication systems, local scatterers in the vicinity of the sources cause angular spreading of radiating signals as seen from a base station antenna array. Thus, the base station antenna array is typically situated on the roof of a high building away from potential multipath reflectors. The uniform circular array (UCA) geometry provides 360° azimuthal coverage and also provides information on source elevation angles. We consider the problem of two-dimensional (azimuth and elevation) direction-of-arrival (DOA) estimation with UCA. In the multipath scenario, the base station antenna can receive many coherent signals that cause the array manifold to be different from the conventional array manifold model. Herein, parameters of the spatial signature in the presence of local scattering are presented which apply to UCA. Then, we present a fast searching technique to improve the efficiency of the MUSIC algorithm for two-dimensional DOA estimation. The fast signal subspace-based estimation method utilizes the ESPRIT algorithm and then adopts sequential one-dimensional searching to save computational cost. Several simulation results are included for illustration and comparison.

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“…The second substitution involves a ''whitening'' process which replaces the noise part in R x by n 2 I M 1 N 1 , where n 2 is an estimate of the noise power. 13 This is necessary since the subarray beamformer is to be applied on a regular subarray and should optimize itself with respect to the corresponding noise-correlation structure, which is n 2 I M 1 N 1 . With the substitutions of ͑41͒ in ͑12͒, we obtain the LCMV subarray weight vector:…”

Section: A Subarray Beamformermentioning

confidence: 99%

Development and analysis of a two-stage beamformer for multiple correlated interferers using rectangular array

Lin

Lee

1999

The Journal of the Acoustical Society of America

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A two-stage two-dimensional ͑2-D͒ beamformer is proposed for signal enhancement in an environment of multiple correlated interferers using a rectangular array. In the first stage, subarray beamformers are constructed which exhibit reliable interference cancellation using differencepreprocessed and spatially smoothed data. A secondary combining of all possible subarray beamformers is then performed to fully exploit the array aperture. It is shown that, compared to the conventional one-stage optimum beamformer, the two-stage beamformer performs equally well and requires a much lower complexity of implementation when a suitable subarray size is chosen.

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On estimating the noise power in array processing

Cited by 34 publications

References 7 publications

Blind beamforming for rectilinear signals

Blind beamforming for rectilinear signals

Subspace‐based techniques for 2‐d DOA estimation with uniform circular array under local scattering

Development and analysis of a two-stage beamformer for multiple correlated interferers using rectangular array

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