Signal processing applications of oblique projection operators

Behrens, R.T.; Scharf, Louis L.

doi:10.1109/78.286957

Cited by 402 publications

(302 citation statements)

References 15 publications

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“…A useful geometric approach to the problem of estimation in the presence of subspace interference has been described in Behrens and Scharf (1994) and serves as the basis of our analysis. The maximum likelihood estimate of h is written as…”

Section: Estimation Efficiencymentioning

confidence: 99%

Detection Power, Estimation Efficiency, and Predictability in Event-Related fMRI

et al. 2001

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Experimental designs for event-related functional magnetic resonance imaging can be characterized by both their detection power, a measure of the ability to detect an activation, and their estimation efficiency, a measure of the ability to estimate the shape of the hemodynamic response. Randomized designs offer maximum estimation efficiency but poor detection power, while block designs offer good detection power at the cost of minimum estimation efficiency. Periodic single-trial designs are poor by both criteria. We present here a theoretical model of the relation between estimation efficiency and detection power and show that the observed trade-off between efficiency and power is fundamental. Using the model, we explore the properties of semirandom designs that offer intermediate trade-offs between efficiency and power. These designs can simultaneously achieve the estimation efficiency of randomized designs and the detection power of block designs at the cost of increasing the length of an experiment by less than a factor of 2. Experimental designs can also be characterized by their predictability, a measure of the ability to circumvent confounds such as habituation and anticipation. We examine the relation between detection power, estimation efficiency, and predictability and show that small increases in predictability can offer significant gains in detection power with only a minor decrease in estimation efficiency.

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Section: Estimation Efficiencymentioning

confidence: 99%

Detection Power, Estimation Efficiency, and Predictability in Event-Related fMRI

et al. 2001

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“…In this case, oblique projector [28,29] has been introduced. Contrary to the orthogonal projection is idempotent and Hermitian, the oblique one is idempotent and not Hermitian.…”

Section: Bsementioning

confidence: 99%

Improved Blind Source Extraction for Time Delay Estimate in Passive Coherent Location System

Zhang

Wang²,

Li³

et al. 2012

PIER B

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Abstract-Target localization is one challenge in passive coherent location (PCL) radar system, and the time delay is the most important parameter in the location. The difficulty of time delay estimate (TDE) in PCL system is that the target signal is completely buried in direct path signal, multipath and clutter (DMC). The conventional clutter cancellation algorithms in matched filter (MF) are time consuming. In this paper, we propose a time delay estimate method based on blind source extraction (BSE) which directly extract the target signal from the mixed signals, thus a new passive coherent location system is built. In this model, the reference antenna is not needed any more. For low signal to interference plus noise ratio (SINR) and frequency overlapped signals in passive coherent location, we introduce the cyclostationarity to enhance the target signal. The experiments on FM broadcast signals show that the computational burden of the proposed algorithm is extremely small and the improved SNR satisfies the location requirements of PCL system.

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“…Based on the previous researches, this paper discusses the uncorrelated characteristic between echoes and jamming based the "thumbtack" feature of LFM signal in FRFT domain [5]. Finally, build an oblique projection operator according to [6] and [7] to suppress the jamming. With the application of the oblique projection, jamming suppression can be processed instantaneously.…”

Section: Introductionmentioning

confidence: 99%

LFM Radar Convolution Jamming Suppression Based on Oblique Projection in FrFT Domain

Wang

Ping

Zhao

et al. 2016

MATEC Web of Conferences

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Abstract. Convolution false-targets jamming against LFM fire-control radars generates range and velocity false targets which are coherent with target echo, which increases the difficulty of jamming detection and suppression and makes the victim radar system lost the track of real target. To combat against this type of jamming, the uncorrelated characteristic between the jamming and echo in FRFT domain is discussed firstly. Thus, an oblique projection operator which is capable of suppress convolution false-targets jamming is built. The simulation results showed the operator have little effect on the echo and proved the effectiveness of this method.

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Signal processing applications of oblique projection operators

Cited by 402 publications

References 15 publications

Detection Power, Estimation Efficiency, and Predictability in Event-Related fMRI

Detection Power, Estimation Efficiency, and Predictability in Event-Related fMRI

Improved Blind Source Extraction for Time Delay Estimate in Passive Coherent Location System

LFM Radar Convolution Jamming Suppression Based on Oblique Projection in FrFT Domain

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