Convergence properties of the multistage constant modulus array for correlated sources

Mathur, Abhishek; Keerthi, A.V.; Shynk, J.J.; Gooch, R.P.

doi:10.1109/78.552231

Cited by 16 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the purpose of blind source separation, an additional complication is that only a single source is found at a time. To recover the other signals successively or in parallel, the previous solutions have to be removed from the data, or independence constraints must be introduced, with additional complications for the convergence [11], [14]- [16], [21], [23].…”

Section: Introductionmentioning

confidence: 99%

Asymptotic properties of the algebraic constant modulus algorithm

Veen

2001

IEEE Trans. Signal Process.

View full text Add to dashboard Cite

Abstract-The algebraic constant modulus algorithm (ACMA) is a noniterative blind source separation algorithm. It computes jointly beamforming vectors for all constant modulus sources as the solution of a joint diagonalization problem. In this paper, we analyze its asymptotic properties and show that (unlike CMA) it converges to the Wiener beamformer when the number of samples or the signal-to-noise ratio (SNR) goes to infinity. We also sketch its connection to the related JADE algorithm and derive a version of ACMA that converges to a zero-forcing beamformer. This gives improved performance in applications that use the estimated mixing matrix, such as in direction finding.Index Terms-Array signal processing, blind beamforming, constant modulus algorithm, simultaneous diagonalization.

show abstract

Section: Introductionmentioning

confidence: 99%

Asymptotic properties of the algebraic constant modulus algorithm

Veen

2001

IEEE Trans. Signal Process.

View full text Add to dashboard Cite

show abstract

“…The performance of the second stage thus depends only on the gain factor for user 3 in the second stage, which can be expressed as (25) The corresponding gain factor for user 2 is (26) Comparing these expressions, we see that the maximum value of is 1, and this happens only when . Since user 2 is stronger than the remaining users, this result can be generalized to an -user system, and it can be shown that .…”

Section: Analysis Of Sinr and Sir Componentsmentioning

confidence: 98%

“…It was shown in [26] that for correlated signals, the Wiener solution for the weights in the first stage of the cascade CM array are given by (32) where is the th column of the correlation matrix . The corresponding Wiener solution for the canceler weights is…”

Section: E Correlated Sourcesmentioning

confidence: 99%

A Multistage Hybrid Constant Modulus Array With Constrained Adaptation for Correlated Sources

Venkataraman

Shynk

2007

IEEE Trans. Signal Process.

View full text Add to dashboard Cite

The multistage constant modulus (CM) array was previously proposed for capturing multiple received signals in a cochannel signal environment. It consists of a cascade of individual CM array stages combined with adaptive signal cancelers that remove the various signals captured across the stages. However, when the received signals are mutually correlated, the signals captured by the CM array stages are not completely canceled, and previous parallel extensions of the system do not guarantee that different signals will be captured across the stages. In this paper, we present a hybrid implementation of the multistage CM array for separating correlated signals where the canceler weights in the cascade structure provide estimates of the direction vectors of the captured signals. These estimates are then used in a parallel implementation of the linearly constrained CM (LCCM) array leading to the hybrid structure. Since the direction vectors are obtained directly from the canceler weights, the hybrid implementation does not require prior knowledge of the array response matrix and is independent of the type of antennas used in the receiver. The effect of a bias in the direction vector estimates for closely-spaced signals is analyzed, and the steady-state performance of the hybrid structure is compared to that of a conventional constrained implementation for correlated sources. Computer simulations for example cochannel scenarios are provided to illustrate various properties of the system. Mean-square-error (MSE) learning curves indicate that the proposed hybrid LCCM algorithm converges faster and has lower MSE than previous implementations.Index Terms-Adaptive array signal processing, blind signal separation, constrained adaptive beamforming, interference suppression.

show abstract

“…We can use an adaptive signal canceller as a simple steering vector estimator, instead of using a complicated DOA estimator. If the signal canceller is applied to subtracting the output of the beamformer from its input signal, the coefficients of the signal canceller are converged to the steering vector of the desired signal [6] [7]. Using these coefficients, the error of the spatial prefilter can be corrected.…”

Section: Introductionmentioning

confidence: 99%

Blind beamforming robust to directional error in fixed wireless channel

Hwang

Lee

12th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications. PIMRC 2001. Proceedings (Cat. No.01TH859

View full text Add to dashboard Cite

Some blind beamformers require the direction of the desired signal. The performance of such type beam-formers can be severely degraded by a small directional error. In this paper, we propose a blind beamforming scheme robust to directional error by employing a simple steering vector estimator. The performance of the proposed beamformer can be further improved by re-initializing the weights of the beamformer.

show abstract

Convergence properties of the multistage constant modulus array for correlated sources

Cited by 16 publications

References 13 publications

Asymptotic properties of the algebraic constant modulus algorithm

Asymptotic properties of the algebraic constant modulus algorithm

A Multistage Hybrid Constant Modulus Array With Constrained Adaptation for Correlated Sources

Blind beamforming robust to directional error in fixed wireless channel

Contact Info

Product

Resources

About