Abstract: Example embodiments relate to methods for distance determination. One embodiment includes a method for determining a distance between a first radio signal transceiver and a second radio signal transceiver. The method includes receiving a first set and a second set of measurement results. The first set is acquired by the first radio signal transceiver based on signals transmitted from the second radio signal transceiver and the second set is acquired by the second radio signal transceiver based on signals transmitted from the first radio signal transceiver. The first set is representable as including, for each of a plurality of frequencies, a measurement pair. The method also includes calculating, for each frequency of the plurality of frequencies, a preliminary estimate of a value proportional to a one-way frequency domain channel response. Additionally, the method includes determining a final estimate of the value proportional to the one-way frequency domain channel response.

Abstract: A device for calculating an indication of power of a received radio signal is disclosed. In one aspect, the device includes a receiver for receiving a plurality of logarithmic values representing a sequence of measurements of power of the received radio signal, and circuitry for determining a sum of the plurality of logarithmic values. The circuitry includes an adder for pairwise summing of two logarithmic values and a plurality of memory registers. The plurality of memory registers are arranged to store intermediate sums of logarithmic values. The circuitry is arranged to control the adder to sum the plurality of logarithmic values by a recursive procedure such that the first and the second logarithmic value in individual summations of the recursive procedure represent substantially same number of power measurements.

Abstract: A device for calculating an indication of power of a received radio signal is disclosed. In one aspect, the device includes a receiver for receiving a plurality of logarithmic values representing a sequence of measurements of power of the received radio signal, and circuitry for determining a sum of the plurality of logarithmic values. The circuitry includes an adder for pairwise summing of two logarithmic values and a plurality of memory registers. The plurality of memory registers are arranged to store intermediate sums of logarithmic values. The circuitry is arranged to control the adder to sum the plurality of logarithmic values by a recursive procedure such that the first and the second logarithmic value in individual summations of the recursive procedure represent substantially same number of power measurements.