A blind adaptive antenna system for the estimation of mutually correlated cochannel sources

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

doi:10.1109/milcom.1995.483628

Cited by 5 publications

(3 citation statements)

References 12 publications

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“…The output power of user 1 in the second stage depends on the gain factor . Substituting (19), this gain becomes (24) Thus, since this is exactly zero, from the previous SINR and SIR expressions, we see that user 1 does not contribute any interference in the second stage of the parallel LCCM array, even though user 1 is stronger than user 2. The biased direction vector does not allow any interference from user 1 to affect the second stage.…”

Section: Analysis Of Sinr and Sir Componentsmentioning

confidence: 87%

“…For this situation, the canceler vectors are accurate estimates of the source direction vectors and thus are appropriate directional constraints for the parallel LCCM array implementation. However, if the signal AOAs are not well separated, then the are not negligible and the canceler vector in the th stage is a biased direction vector given by (19) where…”

Section: Direction Vector Bias Sinr and Sirmentioning

confidence: 99%

“…A parallel implementation of the CM array was considered in [18] where an AOA estimate is used to derive the initial weight vectors of the parallel stages. A hybrid implementation of the CM array was presented in [19] where composite weights of the cascade CM array system are copied to initialize the parallel system. However, it is possible that multiple stages for both of these implementations will capture the same signal because each parallel stage has the same input.…”

Section: Introductionmentioning

confidence: 99%

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

Venkataraman

Shynk

2007

IEEE Trans. Signal Process.

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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.

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Section: Analysis Of Sinr and Sir Componentsmentioning

confidence: 87%

Section: Direction Vector Bias Sinr and Sirmentioning

confidence: 99%