Cell organization and transmission schemes in a wide area positioning system (WAPS)
First Claim
1. A method for reducing cross-interference of a first positioning signal having a first pseudorandom ranging signal upon a second positioning signal having a second pseudorandom ranging signal, the method comprising:
- reducing cross-interference of the first positioning signal upon the second positioning signal by tuning a receiver to a frequency of the second positioning signal and correlating the second positioning signal with a reference pseudorandom ranging signal matched to the second pseudorandom ranging signal,wherein the first and second positioning signals are included among a plurality of two or more positioning signals concurrently transmitted by a plurality of transmitters located at different locations,wherein each of the plurality of positioning signals includes a respective pseudorandom ranging signal modulated on a carrier having a carrier frequency selected from a finite set of values,wherein the first pseudorandom ranging signal of the first positioning signal is modulated on one carrier having a first carrier frequency,wherein the second pseudorandom ranging signal of the second positioning signal is modulated on one carrier having a second carrier frequency that is offset from the first carrier frequency by an offset that is less than or equal to twenty-five percent of the bandwidth of each positioning signal of the first and second positioning signals.
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Accused Products
Abstract
A position location system comprises transmitters that broadcast positioning signals. Each broadcasted positioning signal comprises a pseudorandom ranging signal. The position location system includes a remote receiver that acquires and measures the time of arrival of the positioning signals received at the remote receiver. During an interval of time, at least two positioning signals are transmitted concurrently by the transmitters and received concurrently at the remote receiver. The two positioning signals have carrier frequencies offset from one another by an offset that is less than approximately twenty-five percent of the bandwidth of each positioning signal of the two positioning signals. Cross-interference between the positioning signals is reduced by tuning the remote receiver to a frequency of a selected signal of the two positioning signals and correlating the selected signal with a reference pseudorandom ranging signal matched to a transmitted pseudorandom ranging signal of the selected signal.
208 Citations
73 Claims
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1. A method for reducing cross-interference of a first positioning signal having a first pseudorandom ranging signal upon a second positioning signal having a second pseudorandom ranging signal, the method comprising:
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reducing cross-interference of the first positioning signal upon the second positioning signal by tuning a receiver to a frequency of the second positioning signal and correlating the second positioning signal with a reference pseudorandom ranging signal matched to the second pseudorandom ranging signal, wherein the first and second positioning signals are included among a plurality of two or more positioning signals concurrently transmitted by a plurality of transmitters located at different locations, wherein each of the plurality of positioning signals includes a respective pseudorandom ranging signal modulated on a carrier having a carrier frequency selected from a finite set of values, wherein the first pseudorandom ranging signal of the first positioning signal is modulated on one carrier having a first carrier frequency, wherein the second pseudorandom ranging signal of the second positioning signal is modulated on one carrier having a second carrier frequency that is offset from the first carrier frequency by an offset that is less than or equal to twenty-five percent of the bandwidth of each positioning signal of the first and second positioning signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A non-transitory processor readable memory storing an application adapted to run on at least one processor to implement a method for reducing cross-interference of a first positioning signal having a first pseudorandom ranging signal upon a second positioning signal having a second pseudorandom ranging signal, the method comprising:
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reducing cross-interference of the first positioning signal upon the second positioning signal by tuning a receiver to a frequency of the second positioning signal and correlating the second positioning signal with a reference pseudorandom ranging signal matched to the second pseudorandom ranging signal, wherein the first and second positioning signals are included among a plurality of two or more positioning signals concurrently transmitted by a plurality of transmitters located at different locations, wherein each of the plurality of positioning signals includes a respective pseudorandom ranging signal modulated on a carrier having a carrier frequency selected from a finite set of values, wherein the first pseudorandom ranging signal of the first positioning signal is modulated on one carrier having a first carrier frequency, wherein the second pseudorandom ranging signal of the second positioning signal is modulated on one carrier having a second carrier frequency that is offset from the first carrier frequency by an offset that is less than or equal to twenty-five percent of the bandwidth of each positioning signal of the first and second positioning signals. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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50. A system for reducing cross-interference of a first positioning signal having a first pseudorandom ranging signal upon a second positioning signal having a second pseudorandom ranging signal, wherein the system:
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reduces cross-interference of the first positioning signal upon the second positioning signal by tuning a receiver to a frequency of the second positioning signal and correlating the second positioning signal with a reference pseudorandom ranging signal matched to the second pseudorandom ranging signal, wherein the first and second positioning signals are included among a plurality of two or more positioning signals concurrently transmitted by a plurality of transmitters located at different locations, wherein each of the plurality of positioning signals includes a respective pseudorandom ranging signal modulated on a carrier having a carrier frequency selected from a finite set of values, wherein the first pseudorandom ranging signal of the first positioning signal is modulated on one carrier having a first carrier frequency, wherein the second pseudorandom ranging signal of the second positioning signal is modulated on one carrier having a second carrier frequency that is offset from the first carrier frequency by an offset that is less than or equal to twenty-five percent of the bandwidth of each positioning signal of the first and second positioning signals. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73)
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Specification