Target Localization Using Time-Modulated Directional Modulated Transmitters

In this paper, a target location scheme for multi-target localization in free space is proposed. It exploits the properties of directional modulated antenna radiation patterns which are synthesized using time-modulated arrays (TMAs). Here, we show that the TMAs can be made to synthesize directional modulation (DM) symbols concurrently upon multiple angular beams. Compared with previous DM works on target localization, our proposed system exhibits some promising features, such a i) generating multiple beams simultaneously, enabling multiple targets detection at the same time along different angular directions, ii) allowing multiple access in frequency domain, iii) requiring only one radio frequency (RF) chain with a signal peak- to-average power ratio (PAPR) of 0 dB; iv) eliminating the azimuth ambiguity in mirror angular directions with respect to array boresight, v) flexibly adjusting the target angular resolution, and vi) enabling beam steering without the need of phase shifters. The proposed technique is useful in various applications, such as tracking and controlling multiple drones, vehicles, and etc. It provides an alternative means in most of the Radar applications, and with the capability of wireless communication, it can be treated in the domain of waveform design for the Integrated Sensing and Communication (ISAC).