Ranging in UMTS networks
First Claim
1. A method for determining an approximate range from a location measurement unit (“
- LMU”
) to a mobile device, comprising;
(a) receiving at said LMU an uplink signal from said mobile device;
(b) determining an uplink frame marker from said uplink signal;
(c) receiving at said LMU a first downlink signal from a base station serving said mobile device and a second downlink signal from a neighboring base station;
(d) determining a downlink slot marker from said first downlink signal by correlating all received downlink signals for a predetermined chip delay and non-coherently adding all correlated signals;
(e) determining a round trip propagation delay based on said uplink frame marker and said downlink slot marker; and
(f) determining an approximate range from said LMU to said mobile device as a function of said round trip propagation delay.
19 Assignments
0 Petitions
Accused Products
Abstract
A method and system for determining an approximate range from a location measurement unit to a mobile device. An uplink signal from the mobile device is received by the location measurement unit, and an uplink frame marker is determined from the uplink signal. A downlink signal is received at the location measurement unit from a base station serving the mobile device, and a downlink slot marker is determined from the downlink signal. A round trip propagation delay is determined based upon the uplink frame marker and the downlink slot marker, and an approximate range from the location measurement unit to the mobile device is determined as a function of the round trip propagation delay.
173 Citations
27 Claims
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1. A method for determining an approximate range from a location measurement unit (“
- LMU”
) to a mobile device, comprising;(a) receiving at said LMU an uplink signal from said mobile device; (b) determining an uplink frame marker from said uplink signal; (c) receiving at said LMU a first downlink signal from a base station serving said mobile device and a second downlink signal from a neighboring base station; (d) determining a downlink slot marker from said first downlink signal by correlating all received downlink signals for a predetermined chip delay and non-coherently adding all correlated signals; (e) determining a round trip propagation delay based on said uplink frame marker and said downlink slot marker; and (f) determining an approximate range from said LMU to said mobile device as a function of said round trip propagation delay. - View Dependent Claims (2)
- LMU”
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3. A method for determining an approximate range from a location measurement unit (“
- LMU”
) to a mobile device, comprising;(a) receiving at said LMU an uplink signal from said mobile device; (b) determining an uplink frame marker from said uplink signal; (c) receiving at said LMU a downlink signal from a base station serving said mobile device; (d) determining a downlink slot marker from said downlink signal; (e) determining a round trip propagation delay based on said uplink frame marker and said downlink slot marker; and (f) determining an approximate range from said LMU to said mobile device as a function of said round trip propagation delay, wherein said downlink slot marker is a function of the following relationship;
0≦
nUL−
((tDL−
tUL)R+nDL−
512N)<
512,wherein tUL is the time stamp of said uplink signal, tDL is the time stamp of said downlink signal, NUL is the time of arrival of said uplink frame marks, nDL is the location of said downlink slot marker, R is a sample rate, and N is an integer.
- LMU”
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4. A method for determining an approximate range from a location measurement unit (“
- LMU”
) to a mobile device, comprising;(a) receiving at said LMU an uplink signal from said mobile device; (b) determining an uplink frame marker from said uplink signal, wherein determining the uplink frame marker includes; (i) determining a first time stamp for said uplink signal, and (ii) determining a number of samples between said first time stamp and said uplink frame marker; (c) receiving at said LMU a downlink signal from a base station serving said mobile device; (d) determining a downlink slot marker from said downlink signal, wherein determining the downlink slot marker includes; (i) determining a second time stamp for said downlink signal, and (ii) determining a number of samples between said second time stamp and said downlink slot marker; (e) determining a round trip propagation delay based on said uplink frame marker and said downlink slot marker, wherein determining the round trip propagation delay includes; (i) shifting said downlink slot marker a number of samples such that the number of samples between said uplink frame marker and said downlink slot marker is less than 512, and (ii) determining the number of samples between said uplink frame marker and said shifted downlink slot marker; and (f) determining an approximate range from said LMU to said mobile device as a function of said round trip propagation delay. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- LMU”
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18. A communications network for determining an approximate range to a mobile device, comprising:
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(a) a location measurement unit (“
LMU”
) for receiving an uplink signal from a mobile device;(b) circuitry for determining an uplink frame marker from said uplink signal, wherein the circuitry for determining the uplink frame marker includes circuitry for; (i) determining a first time stamp for said uplink signal, and (ii) determining a number of samples between said first time stamp and said uplink frame marker; (c) a base station serving said mobile device for transmitting a downlink signal to said LMU; (d) circuitry for determining a downlink slot marker from said downlink signal, wherein the circuitry for determining the downlink slot marker includes circuitry for; (i) determining a second time stamp for said downlink signal, and (ii) determining a number of samples between said second time stamp and said downlink slot marker; (e) circuitry for determining a round trip propagation delay based on said uplink frame marker and said downlink slot marker, wherein the circuitry for determining the round trip propagation delay includes circuitry for; (i) shifting said downlink slot marker a number of samples such that the number of samples between said uplink frame marker and said downlink slot marker is less than 512; and (ii) determining the number of samples between said uplink frame marker and said shifted downlink slot marker; and (f) circuitry for determining an approximate range from said LMU to said mobile device as a function of said round trip propagation delay. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification