Array pattern synthesis techniques for circular array of antennas for passive radar applications

We investigate the design of phased array pattern synthesis for applications in passive radars. In particular, we identify certain drawbacks associated with the Bucci algorithm based beamformer design and investigate a convex optimization based approach. The performance is compared in terms of least squares errors and the capability of placing nulls in the direction of interference signals using a circular array of antennas

Beam space transformation based Direction of Arrival estimation and auto calibration for a Circular Array in passive radar

We investigate the capability of beam space transformation based Direction of Arrival (DoA) estimation algorithms and an auto calibration method for the application in passive radar systems using real field measurements. For this, we considered three different DoA methods: Taylor, Minimum Variance Distortionless Response (MVDR)-Capon and a modified Bucci algorithm. All these methods employ phase mode excitation-based beamspace transformation. We also investigate the ability of the Uniform Circular Array (UCA) to perform self-calibration directly from the received DVB-T signal. The results have confirmed satisfactory estimation and detection performance

Preliminary experimental results of polarimetric detection schemes for DVB-T based passive radar

Suitable methods to jointly exploit the diversity of information conveyed by different polarimetric channels in Passive Coherent Location (PCL) systems are a topic of current research. Possible signal processing strategies were devised for FM radio based PCL with the purpose of enhancing the target detection capability and their benefits were largely demonstrated. This paper presents the results from a preliminary investigation carried out considering a multi-channel PCL system exploiting DVB-T signals. The performance improvements yield by different polarimetric detection schemes are analyzed comparatively using an experimental data set. The employed multichannel PCL system PARASOL, from Fraunhofer FHR, features two linearly orthogonally polarized receiving channels. The results obtained show that a polarimetric-Generalized Likelihood Ratio Test (P-GLRT) detection scheme yields a remarkable improvement in terms of detection capability, with respect to both the exploitation of a single polarization and to the non-coherent integration of the information conveyed by the different polarimetric channels

Multipath clutter cancellation and tracking algorithms for passive radars

We demonstrate the ability of a passive radar system to monitor a large area of interest by applying advanced multipath clutter cancellation algorithm, spatial beamforming and tracking techniques. The mitigation of clutter disturbance and a two stage beamforming method facilitate real time tracking of small to moderate size targets in real Cartesian domain. The results have been validated through a real data acquisition campaign performed using an eleven element array antenna based passive radar developed at FHR Institute in Germany

An SINR balancing based multiuser relaying scheme

We consider a relay network with multiple users and propose a signal-to-interference and noise-ratio (SINR) balancing based relay signal forwarding scheme. Each relay receives a combined signal from multiple sources and processes it using a complex valued scalar and transmits towards the destinations so that the SINR at the receiver of each user is maximised. We solve this problem using semidefinite and geometric programming along with bisection search methods. The performance of the proposed scheme has been studied in terms of worst case SINR for various numbers of users and relays. © 2010 IEEE

An SINR balancing based multiuser relaying scheme

We consider a relay network with multiple users and propose a signal-to-interference and noise-ratio (SINR) balancing based relay signal forwarding scheme. Each relay receives a combined signal from multiple sources and processes it using a complex valued scalar and transmits towards the destinations so that the SINR at the receiver of each user is maximised. We solve this problem using semidefinite and geometric programming along with bisection search methods. The performance of the proposed scheme has been studied in terms of worst case SINR for various numbers of users and relays. © 2010 IEEE