Cross-ambiguity characterization of communication waveform features for passive radar

LTE‐based multistatic passive radar system for UAV detection

“…Passive radar systems using the broadcast communication systems as the transmitter of opportunity have been under intensive research in recent years. The potential candidates for the passive radar applications considered in the previous works include the Wi‐Fi transmitters [1–3], the digital video broadcast transmitters [4–7], the digital audio broadcast transmitters [6, 7], and the mobile phones base‐station transmitters [7–14]. Using the long‐term evolution (LTE) downlink signals as the illuminators for the passive radar was considered in [7, 10–14], and a detailed ambiguity function (AF) analysis of the LTE signals and its deterministic features was given in [7, 10, 13].…”

LTE Signals for Device-Free Crowd Density Estimation Through CSI Secant Set and SVD

“…It is evident that when the number of people is low (e.g. 1-2), the curve is less steep, while when it is high (e.g., [4][5][6][7][8][9][10][11][12][13][14][15][16], the curve is steeper. Therefore, we propose to use as features metrics characterizing the trend of this curve.…”

“…They could be available in areas where the WiFi coverage is not present, such as remote and small railways stations or large open spaces, as city squares or stadiums. Most of the works are based on the use of LTE signals with a passive radar approach [8], [9], and not specifically for crowd counting, but for other applications such as localization and target tracking [10]- [12].…”

Disambiguation of interferometric DOA estimates in vehicular passive radar

“…Consequently, many passive radars exploit OFDM‐based systems as illuminators of opportunity. A noise‐free reference signal is obtained by decoding a received OFDM signal and reconstructing it, possibly introducing mismatch to exploit signal features [1–6]. The presence of direct path in the surveillance signal can be mitigated by null steering [1] or by filtering out zero‐Doppler components [7, 8].…”