Method for estimating the distance of a receiver from a radio transmitter, relative methods for calculating the position of a mobile terminal, mobile terminal and localization device
First Claim
1. A method for estimating a distance of a mobile terminal comprising a radio receiver, from at least one base station comprising a radio transmitter, comprising the steps of:
- receiving, at said radio receiver, radio signals irradiated by said radio transmitter, said radio signals corresponding to an OFDM signal comprising a plurality of subcarriers from which a plurality of corresponding tones is extractable;
extracting from said subcarriers of said OFDM signal at least three tones, each having a different frequency;
measuring a first phase difference between a first two tones of said at least three tones, whose frequencies have a first spacing, and measuring a second phase difference between a second two tones of said at least three tones, whose frequencies have a second spacing, wherein one of said first spacing or second spacing is greater than the other;
estimating said distance on a basis of said first phase difference and said second phase difference; and
correcting the estimated distance based on characteristics of a transfer function of a radio channel that includes the OFDM signal, the transfer function being related to a periodicity interval of a distortion present in a frequency spectrum of the radio channel, said distortion characterizing the signal path which separates said base station from said radio receiver.
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Accused Products
Abstract
A method for estimating the distance (d) of a receiver (102) from a radio transmitter (101) includes the steps of: receiving (602) radio signals (103, 701) irradiated by the transmitter (101), which include components from which at least three tones (1,2,3,4) are extracted, each having a different frequency; measuring (606) a first phase difference (Δφ21) between first two tones (1, 2) of the at least three tones, whose frequencies (f1, f2) have a first spacing, and measuring a second phase difference (Δφ43) between second two tones (3, 4) of the at least three tones, whose frequencies (f3, f4) have a second spacing, wherein one of the first spacing or second spacing is greater than the other; estimating (607, 611, 613) the distance (d) on the basis of the first phase difference (Δφ21) and the second phase difference (Δφ43).
28 Citations
9 Claims
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1. A method for estimating a distance of a mobile terminal comprising a radio receiver, from at least one base station comprising a radio transmitter, comprising the steps of:
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receiving, at said radio receiver, radio signals irradiated by said radio transmitter, said radio signals corresponding to an OFDM signal comprising a plurality of subcarriers from which a plurality of corresponding tones is extractable; extracting from said subcarriers of said OFDM signal at least three tones, each having a different frequency; measuring a first phase difference between a first two tones of said at least three tones, whose frequencies have a first spacing, and measuring a second phase difference between a second two tones of said at least three tones, whose frequencies have a second spacing, wherein one of said first spacing or second spacing is greater than the other; estimating said distance on a basis of said first phase difference and said second phase difference; and correcting the estimated distance based on characteristics of a transfer function of a radio channel that includes the OFDM signal, the transfer function being related to a periodicity interval of a distortion present in a frequency spectrum of the radio channel, said distortion characterizing the signal path which separates said base station from said radio receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification