A new approach for DVB-T Cross-Ambiguity Function evaluation

In this paper the use of Digital Video Broadcasting-Terrestrial (DVB-T) signals as waveform of opportunity for Passive Bistatic Radar (PBR) is addressed. A new approach for DVB-T Cross-Ambiguity Function (CAF) evaluation is proposed, which exploits a linear filter based on the knowledge of the expected value of the ambiguity function. The proposed approach is able to remove the unwanted deterministic peaks in the CAF due to specific features of the DVB-T signal, as guard intervals and pilots. The performance of the conceived filter is evaluated against simulated data and compared to other existing approaches. It is shown to yield more robust performance in terms of CAF improvement with reduced computational load and system complexity.

I. Introduction

In recent years there has been a renewed interest in Passive Bistatic Radar (PBR), using existing transmitters as illuminators of opportunity to perform target detection and localization [1]. In particular, broadcast transmitters represent some of the most attractive choices for long range surveillance application due to their excellent coverage. The most common signals for PBR in use today are FM radio and UHF television broadcasts [2]–[5] as well as digital transmissions such as Digital Audio Broadcasting (DAB) and Digital Video Broadcasting-Terrestrial (DVB-T) [6]–[9]. Currently, digital broadcasting are proliferating and rapidly replacing the analogue counterparts. Specifically, with reference to television broadcast, a number of countries have already switched or planned to switch to the DVB-T standard. These signals show both excellent coverage and wider frequency bandwidth which result in increased range resolution achievable. Following these considerations, in this paper we focus our attention on DVB-T signals and on the problems arising from their use as opportunity waveform in PBR systems.