Method for one-sided radio-based distance measurement

A method for distance determination between at least two objects, wherein the at least two objects are time- or clock-cycle-synchronized or at least one time- or clock synchronization or correction is carried out between the at least two objects, the method comprising the steps of:

• emitting a plurality of signals by a first object of the at least two objects, wherein at least a first signal is emitted on a first frequency and at least a second signal is emitted on a second frequency different than the first frequency;
• wherein for emitting the first signal and the second signal, the first object switches between the first frequency and the second frequency in a phase-coherent manner with a phase jump of zero, or changes so that upon changing frequencies, the phase jump is known or determined upon transmission;
• receiving the plurality of signals emitted by the first object at a second object of the at least two objects and carrying out phase measurements on at least the first signal and the second signal upon receipt to determine a first phase value for the first signal and a second phase value for the second signal respectively;
• performing a time-of-flight measurement based on knowledge of at least one point in time at which emission of features of the first signal or the second signal took place, thereby determining a distance estimate;
• calculating a phase shift between the first phase value and the second phase;
• determining a distance between the first object and the second object based on the phase shift between the first phase value and the second phase value in relation to a difference in frequency between the first frequency and the second frequency, the distance having an ambiguity;
• and
• resolving the ambiguity in the distance by comparing the distance to the distance estimate determined by the time-of-flight measurement.