CFAR detection for multiple target situations

Abstract-Recently, a novel approach for PN code acquisition of direct sequence code division multipleaccess (DS-CDMA) systems in Rayleigh fading multipath channel was proposed in [1]. The authors considered a combination of adaptive thresholding constant false alarm rate (CFAR) and smart antennas to increase the system capacity and consequently enhance the detection performance. This paper considers still the problem of PN code acquisition for DS-CDMA communication systems over Rayleigh fading channels under the presence of multipath and multiple-access interference (MAI) signals. We propose and analyze an adaptive array acquisition system, which integrates an adaptive thresholding technique based on ordered data variability (ODV) index constant false alarm rate (ODV-CFAR) and digital beamforming where a low complexity least mean square (LMS) algorithm is used to calculate the optimal weighting coefficients. This approach is expected to mitigate interferences caused by the presence of multiple access interference and multipath. Unlike other approaches based on a fixed censoring point when the number of interferences is assumed known, ODV-CFAR processing does not require prior knowledge about the number of interferences. The simulation results show a robust performance of the proposed system in varying mobile communication channels.

Section: Introductionmentioning

confidence: 88%

Section: Odv-cfar Automatic Censoring Processormentioning

confidence: 99%

Pn Code Acquisition Using Smart Antenna and Adaptive Thresholding Cfar Based on Ordered Data Variability for Cdma Communications

Berbra¹,

Barkat²,

Anou³

2014

“…However, most of the works in the literature consider some type of censoring based on a priori knowledge [6][7][8] and some approaches based on automatic censoring of unwanted cells have been proposed in the literature [9,10].…”

Section: Introductionmentioning

confidence: 99%

Automatic Threshold Selection in Os-Cfar Radar Detection Using Information Theoretic Criteria

Magaz¹,

Belouchrani²,

Hamadouche³

2011

Abstract-This paper proposes a new approach for efficiently determining the unwanted interfering samples in the reference window, for the ordered statistics constant false alarm rate detector, based on the application of the information theoretic criteria principle. The proposed processor termed as Forward Automatic Order Selection Ordered Statistics Detector (FAOSOSD) does not require any prior information about the number of interfering targets. The proposed design aims to improve the Ordered Statistics Constant False Alarm Rate detector performance under severe interference situations. The number of interfering targets is obtained by minimizing the information theoretic criteria. Simulation results that illustrate the performance of the proposed method versus the classical OS-CFAR, the AND-CFAR and the OR-CFAR detectors are presented and discussed.

“…In practice, the environment is usually non-homogeneous due to the presence of multiple targets and/or clutter edges in the reference window. However, there is a significant decrease in performance when the assumption of homogeneous environment is not met [6][7][8][9][10]. Modifications of the CA-CFAR schemes (such as the greatest of CFAR and the smallest of CFAR [2]) have been proposed to improve the original CA-CFAR performance for regions with either clutter transitions or multi-target situation.…”

Section: Introductionmentioning

confidence: 99%

A New Adaptive Linear Combined Cfar Detector in Presence of Interfering Targets

Magaz¹,

Belouchrani²,

Hamadouche³

2011

Abstract-In this paper, a new radar constant false alarm rate detector to perform adaptive threshold target detection in presence of interfering targets is proposed. The proposed CFAR detector, referred to as Adaptive Linear Combined CFAR, ALC-CFAR, employs an adaptive composite approach based on the well-known cell averaging CFAR, CA-CFAR, and the ordered statistics, OS-CFAR, detectors. Data in the reference window is used to compute an adaptive weighting factor employed in the fusion scheme. Based on this factor, the ALC-CFAR tailors the background estimation algorithm. The conducted Monte Carlo simulation results demonstrate that the proposed detector provides low loss CFAR performance in an homogeneous environment and also performs robustly in presence of interfering targets. The performances of the ALC-CFAR detector have been evaluated and compared with that of the CA-CFAR and the OS-CFAR detectors. The obtained results are presented and discussed in this paper.