Jens Steinwandt

Learn More
This paper presents a widely-linear (WL) distributed beamform-ing algorithm that takes advantage of strictly second-order (SO) non-circular source signals. We consider a single-antenna source-destination pair, which is assisted by multiple relays but suffers from strong interference. Assuming that perfect channel state information (CSI) is available, we(More)
—High-resolution parameter estimation algorithms designed to exploit the prior knowledge of incident signals from strictly second-order (SO) non-circular (NC) sources allow for a lower estimation error and can detect twice as many sources. In this paper, we derive the R-D NC Standard ESPRIT and the R-D NC Unitary ESPRIT algorithms that provide a(More)
Motivated by the performance of the direction finding algorithms based on the auxiliary vector filtering (AVF) method and the conjugate gradient (CG) method as well as the advantages of operating in beamspace (BS), we develop two novel direction finding algorithms for uniform linear arrays (ULAs) in the beamspace domain, which we refer to as the BS AVF and(More)
High-resolution parameter estimation algorithms designed to benefit from the presence of non-circular (NC) source signals allow for an increased identifiability and a lower estimation error. In this paper , we present a 1-D first-order performance analysis of the NC standard ESPRIT and NC Unitary ESPRIT estimation schemes for strictly second-order (SO)(More)
In this paper, we consider the problem of optimizing the transmit co-variance matrix for a multiple-input multiple-output (MIMO) Gaus-sian wiretap channel. The scenario of interest consists of a transmitter , a legitimate receiver, and multiple non-cooperating eavesdrop-pers that are all equipped with multiple antennas. Specifically, we design the transmit(More)
This paper presents a first-order analytical performance assessment of the 1-D non-circular (NC) Standard ESPRIT and the 1-D NC Uni-tary ESPRIT algorithms both using structured least squares (SLS) to solve the set of augmented shift invariance equations. These high-resolution parameter estimation algorithms were designed for strictly second-order (SO)(More)
—In certain applications involving direction finding, a priori knowledge of a subset of the directions to be estimated is sometimes available. Existing knowledge-aided (KA) methods apply projection and polynomial rooting techniques to exploit this information in order to improve the estimation accuracy of the unknown signal directions. In this paper, a new(More)
We propose a non-data-aided adaptive beamforming algorithm based on Widely Linear (WL) processing techniques and the Auxiliary Vector Filtering (AVF) algorithm for non-circular signals, where only the steering vector of the desired user is known. The proposed Widely Linear Auxiliary Vector Filtering (WL-AVF) algorithm recursively updates the filter weights(More)
Spatial smoothing is a widely used preprocessing scheme to improve the performance of high-resolution parameter estimation algorithms in case of coherent signals or a small number of available snapshots. In this paper, we present a first-order performance analysis of Standard and Unitary ESPRIT as well as NC Standard and NC Unitary ESPRIT for strictly(More)
—It is well known that parameter estimation algorithms designed to exploit the prior knowledge of the strict second-order (SO) non-circularity (NC) of incident signals can estimate the parameters of twice as many sources and achieve significant gains in reducing the estimation error. So far, the magnitude of the NC gain could only be quantified through(More)