I'm wondering if your thesis supervisor had a wicked sense of humour.
With various technologies, you can determine whether two items are "in range" or "out of range".
What they can not in general, is to specify such a range; to reliably distinguish between 10 cm and 10 metres, as firstly, the propagation of radio waves depends on shadowing, absorption, reflection, focussing and such.
Secondly, the "flight time" of radio signals over such distances - such as 10 metres - is in the order of single-digit nanoseconds, so "radar" technologies to measure this require very specialised microwave circuitry.
To be able to do so is a frequently asked question, and such commercial systems as are available to perform this task are very sophisticated - and expensive.
We wish you luck.