Segment-Sliding Reconstruction of Pulsed Radar Echoes with Sub-Nyquist Sampling

摘要

It has been shown that analog-to-information con- version (AIC) is anefficient scheme to perform sub-Nyquist sampling of pulsed radar echoes.However, it is often impractical, if not infeasible, to reconstruct full-rangeNyquist samples because of huge storage and computational load requirements.Based on the analyses of AIC measurement system, this paper develops a novelsegment-sliding reconstruction (SegSR) scheme to effectively reconstruct theNyquist samples. The SegSR per- forms segment-by-segment reconstruction in asliding mode and can be implemented in real-time. An important characteristicthat distinguish the proposed SegSR from the existing methods is that themeasurement matrix in each segment satisfies the restricted isometry property(RIP) condition. Partial support in the previous segment can be incorporatedinto the estimation of the Nyquist samples in the current segment. The effectof interference intro- duced from adjacent segments is theoretically analyzed,and it is revealed that the interference consists of two interference levelshaving different impacts to the signal reconstruction performance. With theseobservations, a two-step orthogonal matching pursuit (OMP) procedure isproposed for segment reconstruction, which takes into account differentinterference levels and partially known support of the previous segment. Theproposed SegSR achieves nearly optimal reconstruction performance with a signi-ficant reduction of computational loads and storage requirements. Theoreticalanalyses and simulations verify its effectiveness.