Beam-based carrier phase positioning

An apparatus comprising:

• one or more processors;
• and
• at least one memory storing instructions that, when executed by the one or more processors, causes the apparatus to:
• select a subset of two or more beam pairs among a set of beam pairs via which a terminal and a base station are associated, wherein for each of the beam pairs of the subset, a suitability of the respective beam pair is better than a suitability threshold;
• for each of the beam pairs of the subset:
• determine a respective set of at least one tone to generate a respective non-local virtual wavelength from one of the tones of the set of at least one tone and a tone of another beam of the subset;
• perform a respective relative phase measurement based on the respective non-local virtual wavelength to obtain a respective non-local virtual phase difference;
• and at least one of
• report the set of tones, the respective beam pair and the other beam pair, and the respective non-local virtual phase difference to the base station;
• and
• estimate a respective distance between the terminal and a transmission reception point of the base station emitting the respective beam pair based on the respective non-local virtual phase difference and the preliminary uncertainty region;
• and
• the respective set of at least one tone is determined such that a respective non- local virtual wavelength λv generated from the tones of two beams of the subset fulfills a condition λv≥2ρ, wherein ρ is a distance from a respective predicted position of the terminal to a boundary of the respective preliminary uncertainty region of the predicted position of the terminal;
• and
• the respective distance between the terminal and the transmission reception point of the base station emitting the respective beam pair is estimated based on the respective relative phase measurement and the preliminary uncertainty region.