Athanassios Manikas

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—In this paper, an asynchronous, multicarrier direct-sequence code-division multiple-access (DS-CDMA) array receiver is proposed based upon blind, composite channel vector estimation. Due to the fact that the combined effect of all received paths is estimated , the total number of paths can be greater than the number of antennas in the receiver array.(More)
— In this paper, the problem of ambiguities inherent in the manifold of any linear array structure is investigated. Ambiguities, which can be classified into trivial and nontrivial, depending on the ease of their identification, arise when an array cannot distinguish between two different sets of directional sources. Initially, the new concept of an(More)
—In this paper, the manifold of a general two-or three-dimensional (2-D or 3-D) array of sensors is studied using differential geometry. By considering the azimuth and elevation angles as the parameters of interest, a manifold surface is formed embedded in a multidimensional complex space. Initially, this surface is investigated by establishing a number of(More)
—This paper is concerned with the design of super-resolution direction finding (DF) arrays that satisfy prespecified performance levels, such as detection-resolution thresholds and Cramér–Rao bounds on error variance. The sensor placement problem is formulated in the framework of subspace-based DF techniques and a novel polynomial rooting approach to the(More)
—In this paper, a blind asynchronous single-user code-reuse direct sequence code division multiple access (CDMA) array receiver is proposed for the uplink. By assigning each short PN-code more than once, code reuse allows the number of active users to be increased beyond the spreading gain. The proposed receiver is based on a blind single-code multipath(More)
— In this paper, a novel approach is proposed for the calculation of ambiguous generator sets of directions for planar arrays. This approach is based on the concept of hyper-helical curves and their equivalent linear arrays, which provide a vehicle for investigating planar array ambiguities by adopting and extending techniques proposed for linear arrays.(More)
In this paper, a blind subspace-type single-user array direct-sequence code division multiple access (DS-CDMA) receiver is proposed based on a new joint space-time channel estimation technique for frequency-selective channels. In the proposed approach, the spatio-temporal multipath channel parameters associated with the desired user are jointly estimated(More)