Algorithms for Real-Time Processing
Abstract
This paper describes methodologies for on-line processing of received radar data by a set of N antennas and M pulse repetition intervals (PRIs) for the calculation of space-time adaptive (STAP) filter output. The numerically robust and computationally efficient QR-decomposition (QRD) is used to derive the so called MVDR (Minimum Variance Distortionless Response) and lattice algorithms; the novel inverse QRD (IQRD) is also applied to the MVDR problem. These algorithms are represented as systolic computational flow graphs. The MVDR is able to produce more than one adapted beams focused along different angular directions and Doppler frequencies in the radar surveillance volume. The lattice algorithm offers a computational saving; in fact, its computational burden is O(N2M) in lieu of O(N2M2). An analysis of the numerical robustness of the STAP computational schemes is presented when the CORDIC (CO-ordinate Rotation Digital Computer) algorithm is used to compute the QRD and the IQRD. Benchmarks on general purpose parallel computers and on a VLSI (Very Large Scale Integrated) CORDIC board are presented. The paper is organized as follows. Section 2 introduces the STAP problem and the basic systolic algorithms to reach real time adaptation. The lattice and its generalization (vectorial lattice) for wideband problems are discussed in section 3. The IQRD based MVDR algorithm is presented in Section 4. Experiments of mapping the basic triangular systolic array onto general purpose parallel computers are discussed in Section 5. The use of VLSI CORDIC board is the theme of Section 6. The MVDR systolic algorithm is applied to off-line process recorded live data; the detection of vehicular traffic is shown (Section 7). Finally, Section 8 gives a perspective for future research.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2003
- Accession Number
- ADP014045
Entities
People
- A. Farina