A method for determining a distance between a first and a second radio signal transceiver, said method comprising: receiving a first set of measurement results and a second set of measurement results, wherein the first set of measurement results is acquired by the first radio signal transceiver based on signals transmitted from the second radio signal transceiver and the second set of measurement results is acquired by the second radio signal transceiver based on signals transmitted from the first radio signal transceiver, the first set of measurement results comprises, for each of a plurality of frequencies, a measurement pair of a phase measurement and a signal strength measurement and the second set of measurement results comprises, for each of said plurality of frequencies, a phase measurement or optionally a measurement pair of a phase measurement and a signal strength measurement; calculating, for each frequency of said plurality of frequencies, a preliminary estimate of a value proportional to a one-way frequency domain channel response, based on the measurement pair from the first set of measurement results and the phase measurement, or optionally the measurement pair, from the second set of measurement results; calculating, for pairs of adjacent frequencies, an estimate of a value proportional to a time synchronization offset between a clock used by the first radio signal transceiver and a clock used by the second radio signal transceiver, wherein the estimate for the value proportional to the time synchronization offset is based on, for each frequency in the pairs of adjacent frequencies, the phase of the calculated preliminary estimate of the value proportional to the one-way frequency domain channel response and the phase measurement, or optionally the measurement pair, from the first set of measurement results and, optionally, a difference in frequency between the frequencies in the pair of adjacent frequencies; determining, for each frequency of said plurality of frequencies, a final estimate of a value proportional to the one-way frequency domain channel response based on the preliminary estimate and adjacent estimates for the value proportional to the time synchronization offset; and determining the distance between the first and the second radio signal transceiver based on said final estimates. receiving a first set of measurement results and a second set of measurement results, wherein the first set of measurement results is acquired by the first radio signal transceiver based on signals transmitted from the second radio signal transceiver and the second set of measurement results is acquired by the second radio signal transceiver based on signals transmitted from the first radio signal transceiver, the first set of measurement results comprises, for each of a plurality of frequencies, a measurement pair of a phase measurement and a signal strength measurement and the second set of measurement results comprises, for each of said plurality of frequencies, a phase measurement or optionally a measurement pair of a phase measurement and a signal strength measurement; calculating, for each frequency of said plurality of frequencies, a preliminary estimate of a value proportional to a one-way frequency domain channel response, based on the measurement pair from the first set of measurement results and the phase measurement, or optionally the measurement pair, from the second set of measurement results; calculating, for pairs of adjacent frequencies, an estimate of a value proportional to a time synchronization offset between a clock used by the first radio signal transceiver and a clock used by the second radio signal transceiver, wherein the estimate for the value proportional to the time synchronization offset is based on, for each frequency in the pairs of adjacent frequencies, the phase of the calculated preliminary estimate of the value proportional to the one-way frequency domain channel response and the phase measurement, or optionally the measurement pair, from the first set of measurement results and, optionally, a difference in frequency between the frequencies in the pair of adjacent frequencies; determining, for each frequency of said plurality of frequencies, a final estimate of a value proportional to the one-way frequency domain channel response based on the preliminary estimate and adjacent estimates for the value proportional to the time synchronization offset; and determining the distance between the first and the second radio signal transceiver based on said final estimates.