Performance analysis of the reference signal reconstruction for DVB-T passive radars

Abstract

The present work investigates the reference signal reconstruction method for passive coherent location (PCL) radars exploiting Digital Video Broadcasting-Terrestrial (DVB-T) signals. The reference signal reconstruction improves the signal-to-noise ratio (SNR) of the reference signal, which enhances the detection probability for DVB-T based PCL systems. The existing approach for the reference signal reconstruction is performed by demodulating the received reference signal to retrieve the transmitted quadrature amplitude modulation (QAM) symbols and modulate them to obtain the reconstructed signal. For low SNR values, the QAM symbol detection is accompanied with a significant error, which leads to a mismatch between the reconstrued signal and the exact one. Consequently, the expected improvement due to the signal reconstruction is limited. In this work, we propose an optimum reconstruction method which filters the detected QAM symbol prior to the remodulation step. To validate the proposed method, we retrieved analytic expressions for the detection and false-alarm probabilities and verified them through Monte-Carlo simulations. In addition, real-data sets were used to evaluate the proposed method performances. The results show that the proposed method outperforms the conventional one by extending the feasibility of the reference signal reconstruction for low SNR values.

Waveform Selection For Multi-Band Multistatic Radar Networks

“…where k B , T 0 and N F denote the Boltzmann's constant (1.38 × 10 −23 J/K), reference temperature (290 K) and receiver noise figure in linear scale. Note that noise in the reference channel can be removed by reconstructing the reference signal in DVB-T and DAB systems since the received signal can be demodulated and then re-modulated to acquire the reference signal without noise [14]. While this method can efficiently reconstruct the reference signal when the SNR is sufficiently high, it is not beneficial in low SNR cases as a significant amount symbols will be erroneously demodulated when the SNR is not sufficient.…”

“…for OFDM signals is given in [28], and substituting this in (14), the first element of the modified FIM for an OFDM waveform consisting of L OFDM symbols can be written as…”

“…However, this signal also includes noise as much as the noise the surveillance signal has. One of the solutions for removing the noise in the reference signal is to demodulate and reconstruct the reference signal if the modulation type of this signal is known [14]. This signal reconstruction was shown to improve the detection performance in DVB-T passive radar systems when the SNR of the reference signal is sufficient for highly accurate demodulation [14].…”

“…One of the solutions for removing the noise in the reference signal is to demodulate and reconstruct the reference signal if the modulation type of this signal is known [14]. This signal reconstruction was shown to improve the detection performance in DVB-T passive radar systems when the SNR of the reference signal is sufficient for highly accurate demodulation [14]. However, for low SNR signals, demodulation of the reference signal will include significant errors, therefore, signal reconstruction techniques may not work well due to the demodulation errors [15,14].…”

Pilot‐based detection for DVB‐T passive coherent location radars

“…This approach is efficient if the initial SNR guarantees a low‐error demodulation of the received signal. For low SNR values, the performance of the signal reconstruction is limited [23, 24].…”