Lagrange-Polynomial-Interpolation-Based Keystone Transform for a Passive Radar

Abstract

In this paper we address the problem of target's range migration in passive bistatic radar exploiting long coherent integration times with fairly wideband signals of opportunity. We resort to the well-known Keystone Transform (KT) to compensate for the range walk effect and to take advantage of a higher coherent integration gain against targets with non-negligible radial velocity. Specifically, an efficient implementation of the KT is proposed, based on Lagrange polynomial interpolation, in order to reduce the computational load of the method that mostly depends on the required slow-time interpolation stage. The analysis conducted against simulated data shows that the conceived approach allows to achieve theoretical performance while further reducing the KT complexity with respect to alternative solutions based on cardinal sine functions or Chirp-Z Transforms. Moreover, the application against experimental data sets collected by a DVB-T based passive radar proves the practical effectiveness of the proposed algorithm and highlights its suitability for real-time air traffic surveillance applications.

Radar Coherent Detection for Maneuvering Target Based on Product-Scaled Integrated Cubic Phase Function

“…To achieve coherent integration, many successful methods have been proposed [14][15][16]. In this paper, the KT is employed for convenience, which scales the slow time for each range frequency:…”

“…For KT-GDP, the KT and fold factor searching are firstly performed to eliminate the LRM, and the computational costs are, respectively, O(3N r M log 2 M) [16] and O(N F MN r log 2 MN r ). e GDP is then employed to estimate the acceleration and jerk, of which the computational cost is at the order of O(MN a N g log 2 M).…”

“…(a) e first category mainly focuses on the LRM caused by the high speed. Representative methods include the keystone transform (KT) [14][15][16], Radon-Fourier transform (RFT) [17][18][19], scaled inverse Fourier transform (SCIFT) [20], frequency-domain deramp-keystone transform (FDDKT) [21], axis rotation MTD (AR-MTD) [10], and modified location rotation transform (MLRT) [22]. Nevertheless, due to ignoring the acceleration and jerk, the signal energy will be dispersed in the Doppler domain.…”

A Sparse Temporal Synchronization Algorithm of Laser Communications for Feeder Links in 5G Nonterrestrial Networks

“…The transformation-domain algorithms [18][19][20][21] follow open loop principle and are able to maintain a constant processing delay in high Doppler environments. In [18], the discrete fractional Fourier transform (DFrFT) was adopted for acceleration and velocity estimation.…”

“…In [20], the authors studied the time-frequency characteristics from the perspective of signal time-frequency distribution, i.e., Wigner-Ville distribution, to facilitate the temporal synchronization. In [21], the keystone transform was employed to solve the target range migration problem in temporal synchronization. Although transformation-domain algorithms are suitable for the scenario with high Doppler, their computational complexity is usually very high, which violates the low power consumption requirement as well.…”