Method and apparatus for estimating the position of a terminal based on identification codes for transmission sources
First Claim
1. A method for determining the location of a device in a wireless communication system, comprising:
- receiving from a transmission source comprising a terrestrial-based wireless repeater at a known location, a first signal having included therein transmitted data and a second signal having included therein an identification code assigned to the transmission source, wherein the identification code comprises a plurality of delayed and attenuated versions of the first signal and representative of a particular multipath profile;
processing the second signal to recover the identification code; and
determining a position estimate of the device based on the recovered identification code.
1 Assignment
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Accused Products
Abstract
Techniques to determine the position of a terminal under the coverage of a repeater in a wireless communication system. In an aspect, an identification code is transmitted for each repeater and used by the terminal (or a PDE) to unambiguously identify the repeater. The identification codes for the repeaters in the system can be implemented with PN sequences at defined offsets that are specifically reserved for repeater identification. In another aspect, the identification code for each repeater is transmitted using a spread-spectrum signal designed to have minimal impact on the performance of the system and to be recoverable by the terminal in similar manner as for a forward modulated signal. In this way, no additional hardware is required for the terminal to recover the identifier signal. In one specific design, the spread spectrum identifier signal is generated in accordance with and conforms to the IS-95 CDMA standard.
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Citations
33 Claims
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1. A method for determining the location of a device in a wireless communication system, comprising:
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receiving from a transmission source comprising a terrestrial-based wireless repeater at a known location, a first signal having included therein transmitted data and a second signal having included therein an identification code assigned to the transmission source, wherein the identification code comprises a plurality of delayed and attenuated versions of the first signal and representative of a particular multipath profile; processing the second signal to recover the identification code; and determining a position estimate of the device based on the recovered identification code. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for determining the location of a device in a wireless communication system, comprising;
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receiving from a transmission source comprising a terrestrial-based wireless repeater at a known location, a first signal having included therein transmitted data and a second signal having included therein an identification code assigned to the transmission source; processing the second signal to recover the identification code; and determining a position estimate of the device based on the recovered identification code; wherein the identification code comprises a signal transmitted at a frequency different from the frequency of the first signal and at a particular transmit offset. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method for generating a signal suitable for use to estimate the location of a device in a wireless communication system, comprising:
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receiving at a transmission source a forward link signal having included therein at least a pilot signal; processing the forward link signal to recover a timing reference, and processing the forward link signal to recover a frequency reference for a carrier signal of the forward link signal, generating at the transmission source a second signal having included therein an identification code assigned to the transmission source; combining the forward link signal and the second signal to provide a combined signal, wherein the second signal is further generated in accordance with the recovered frequency reference and the recovered timing reference; and transmitting the combined signal from the transmission source. - View Dependent Claims (16)
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17. A method for generating a signal suitable for use to estimate the location of a device in a wireless communication system, comprising:
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receiving at a transmission source a forward link signal having included therein at least a pilot signal; generating at the transmission source a second signal having included therein an identification code assigned to the transmission source; combining the forward link signal and the second signal to provide a combined signal; and transmitting the combined signal from the transmission source; wherein the identification code is a pseudo-noise (PN) sequence at a particular offset, and wherein the offset of the PN sequence used for the identification code is one of a plurality of possible offsets and is reserved for identification of the transmission source. - View Dependent Claims (18, 19, 20, 21)
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22. A method for generating a signal suitable for use to estimate the location of a device in a wireless communication system, comprising;
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receiving at a transmission source a forward link signal having included therein at least a pilot signal; generating at the transmission source a second signal having included therein an identification code assigned to the transmission source; combining the forward link signal and the second signal to provide a combined signal; and transmitting the combined signal from the transmission source; wherein the identification code is a pseudo-noise (PN) sequence at a particular offset, and wherein the timing of the PN sequence used for the identification code is approximately aligned with the timing of a PN sequence used to spread the pilot signal.
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23. A method for generating a signal suitable for use to estimate the location of a device in a wireless communication system, comprising:
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receiving at a transmission source a forward link signal having included therein at least a pilot signal; generating at the transmission source a second signal having included therein an identification code assigned to the transmission source; combining the forward link signal and the second signal to provide a combined signal wherein an amplitude of the second signal is set to a particular level below the amplitude of the forward link signal; and transmitting the combined signal from the transmission source.
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24. A method for generating a signal suitable for use to estimate the location of a terminal in a wireless communication system, comprising:
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receiving and processing at a transmission source a forward link signal having included therein at least a pilot signal; generating a second signal having included therein an identification code assigned to the transmission source;
wherein the second signal comprises a plurality of signals at different offsets and representative of a particular multipath profile;transmitting the forward link signal from the transmission source; and transmitting the second signal to a plurality of terminals within the communication system.
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25. A method for generating a signal suitable for use to estimate the location of a terminal in a wireless communication system, comprising:
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receiving and processing at a transmission source a forward link signal having included therein at least a pilot signal; generating a second signal having included therein an identification code assigned to the transmission source wherein the second signal comprises a plurality of pseudo-noise (PN) sequences at a plurality of offsets and representative of a particular multipath profile; transmitting the forward link signal from the transmission source; and transmitting the second signal to a plurality of terminals within the communication system.
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26. A transmission unit in a wireless communication system, comprising:
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a first unit operative to receive, condition, and retransmit signals on both forward and reverse links of the communication system; and a second unit coupled to the first unit and including a first module operative to receive and process a forward link signal having included therein at least a pilot signal, a second module operative to generate a second signal having included therein an identification code assigned to the transmission unit, and a third module operative to combine the forward link signal and the second signal to provide a combined signal for transmission from the transmission unit; wherein the first module is further operative to process the forward link signal to recover a frequency reference for a carrier signal of the forward link signal, and wherein the second signal is further generated in accordance with the recovered frequency reference.
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27. A method for determining the location of a device in a wireless communication system, comprising:
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receiving from a first transmission source a first signal having included therein transmitted data and a second signal having included therein a first identification code assigned to the first transmission source, wherein the first identification code is selected from among a list of identification codes used for nearby transmission sources, wherein the first identification code comprises a plurality of identification codes in the list, and wherein the plurality of identification codes for the first identification code are associated with different offsets; processing the second signal to recover the first identification code; and determining a position estimate of the device based on the recovered first identification code. - View Dependent Claims (28, 29, 30, 31)
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32. A method for determining the location of a device in a wireless communication system, comprising:
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receiving from a first transmission source a first signal having included therein transmitted data and a second signal having included therein a first identification code assigned to the first transmission source, wherein the first identification code is selected from among a list of identification codes used for nearby transmission sources; wherein the identification code assigned to the first transmission source is delayed relative to the first signal by a particular amount of delay; processing the second signal to recover the first identification code; and determining a position estimate of the device based on the recovered first identification code. - View Dependent Claims (33)
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Specification