Telecommunications-assisted satellite positioning system

• US 6,118,977 A
• Filed: 09/11/1997
• Issued: 09/12/2000
• Est. Priority Date: 09/11/1997
• Status: Expired due to Term

• Current Assignee: IDPA Holdings Incorporated (InterDigital, Inc.)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Vannucci, Giovanni
• Primary Examiner(s): Trost, William G.
• Assistant Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US08/927,432
• Time in Patent Office: 1,097 Days
• Field of Search: 455/12.1, 455/13.1, 455/450, 455/456, 455/13.2, 455/502, 455/11.1, 455/427, 455/428, 455/430, 342/357.03, 342/357.09, 342/357.02, 342/357.12, 342/357.16, 342/353, 342/125, 342/146, 342/357.13, 375/208, 375/209, 375/326, 375/741, 375/366, 375/367, 701/213, 701/215
• US Class Current: 455/12.1
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0063 of measured values, i.e. measurement on base station and position calculation on mobile

Abstract

A wireless terminal and auxiliary system are disclosed that enable the wireless terminal to determine its location based on signals transmitted from navigation satellites. In particular, the tasks of signal acquisition and signal processing required of a wireless terminal in the prior art are divided between the wireless terminal and the auxiliary system in accordance with the illustrative embodiment. The auxiliary system assists the wireless terminal by acquiring information about the satellites'"'"' ephemerides, by partially processing it and by transmitting the partially processed information to the wireless terminal in a form that is useful to the wireless terminal. The wireless terminal then uses the partially processed information from the auxiliary system to assist the wireless terminal in acquiring the ranging signals from the navigation satellites quickly and when they are weak.

Claims

1. A wireless terminal comprising:

a telecommunications receiver for receiving a code synchronization estimate for a ranging signal for a satellite from an auxiliary system over a wireless telecommunications link; and

a field receiver for receiving and processing said ranging signal using said code synchronization estimate;

wherein said wireless terminal uses;

said code synchronization estimate to facilitate the creation of a candidate code;

said candidate code and said ranging signal to create a candidate sinusoidal signal; and

a discrete fourier transform of said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.

2. A wireless terminal comprising:

a telecommunications receiver for receiving a modulation bit sequence and a Doppler shift estimate for a ranging signal for a satellite from an auxiliary system over a wireless telecommunications link; and

a field receiver for receiving and processing said ranging signal using said modulation bit sequence and said Doppler shift estimate;

wherein said wireless terminal uses;

a code synchronization estimate to facilitate the creation of a candidate code;

said candidate code, said modulation bit sequence, said Doppler shift estimate, and said ranging signal to create a candidate sinusoidal signal; and

a discrete fourier transform of said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.

3. A wireless terminal comprising:

a telecommunications receiver for receiving a system timing signal and a modulation bit sequence for a satellite over a wireless telecommunications link; and

a field receiver for receiving and processing a ranging signal using said system timing signal

wherein said wireless terminal uses;

a code synchronization estimate to facilitate the creation of a candidate code;

said candidate code, said modulation bit sequence, and said ranging signal to create a candidate sinusoidal signal; and

a discrete fourier transform of said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.

4. A method of operating a wireless terminal, said method comprising:

receiving, with a field receiver, a ranging signal from a satellite;

receiving, with a telecommunications receiver, a code synchronization estimate for said ranging signal from an auxiliary system for processing said ranging signal;

using said code synchronization estimate to facilitate the creation of a candidate code;

processing said ranging signal with said candidate code and to create a candidate sinusoidal signal; and

performing spectral analysis on said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.

5. A method of operating a wireless terminal comprising:

receiving, with a field receiver, a ranging signal from a satellite;

receiving, with a telecommunications receiver, a modulation bit sequence and a code synchronization estimate for said ranging signal from an auxiliary system for processing said ranging signal;

using said code synchronization estimate to facilitate the creation of a candidate code;

processing said ranging signal with said candidate code and said modulation bit sequence to create a candidate sinusoidal signal; and

performing spectral analysis on said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.

6. A method of operating a wireless terminal comprising:

receiving, with a telecommunications receiver, a system timing signal and a code synchronization estimate for said ranging signal;

receiving, with a field receiver from a satellite, a ranging signal;

using said system timing signal and said code synchronization estimate to facilitate the creation of a candidate code;

processing said ranging signal with said candidate code and to create a candidate sinusoidal signal; and

performing spectral analysis on said candidate sinusoidal signal to determine when said candidate code is synchronized with said ranging signal.