Are there any hardware solutions or something, where I can start, for the task I describe here? For example, I have a smartphone with a built-in camera and a special sensor attached (the first hardware device I'm looking for) that "looks" in the same direction as the camera. Next, there is a human in front of me (may be in 3-10 meters). He has a special sensor that is connected to his smartphone and he has an ID number (the second hardware device I'm looking for). Now I aim my camera on this human and the sensor in my smartphone catches the signal sent by that human's sensor. So now I can use my software to identify the man that I see through my camera by ID from his sensor.
Actually, in my opinion, this imagined system doesn't need camera at all. The camera is just a helper tool. For example, if I have no camera but have sensors, I can aim and catch the human in the dark night. If I there two or ten people around me with sensors in their phones, I can see info about them on screen and see their locations relatively to me. I imagine that if a lot of people have phones with such built-in sensors and registered accounts at the system, they can share some info with passer-by if they want. It's something like augmented reality, not for objects around you, but for people. Thank you.