Hybrid opportunistic radar over long term evolution networks

Passive radar systems that use an illuminator of choice have been extensively studied over the past decade because they are difficult to detect and cheaper to deploy. Among the signals investigated for passive radar are FM radio, DVB-T and cellular networks. Recently, UMTS and Long Term Evolution (LTE) signals have been considered for passive radar. In this paper we study specific aspects of LTE signals that make them profoundly different from other signals for passive radars. We show that the LTE protocol can be exploited to serve as an active radar when combined with an LTE enabled receiver. We explain how the transmitted waveforms can be controlled by PMI feedback and from the cellular unit to the base station to form an active MIMO radar.