Cellular positioning system (CPS)

• US 6,111,538 A
• Filed: 02/23/1995
• Issued: 08/29/2000
• Est. Priority Date: 12/23/1994
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Stanford Telecommunications, Inc. (Nokia Corporation)
• Inventors: Weinberg, Aaron, Schuchman, Leonard, Bruno, Ronald, Engelbrecht, Lloyd
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US08/393,312
• Time in Patent Office: 2,014 Days
• Field of Search: 342/357, 342/361, 455/33.1
• US Class Current: 342/357.31
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 2001/6912 using chirp
• CPC Class Codes: H04L 27/103 Chirp modulation for spread spectrum techniques H04B1/69
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a cellular pattern. Each SS broadcasting station include a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent stations in the cellular pattern, each channel signal including navigation beacon data including a unique beacon identification, station latitude and longitude, time_-- slot and phase characterizations and selected parameters of adjacent stations. In one embodiment, each modulator provides a chirped SS signal in which the navigation beacon is a frequency tone that is repeatedly swept over a selected frequency band for each station. In a further embodiment, each modulator provides a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast. A receiver on the mobile body receives the SS signals from at least three of the SS broadcasting stations and determines the location thereof. A fourth SS broadcasting station provides altitude. CPS satellite signals can be used for timing control.

Claims

1. Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a hexagonal cellular pattern, each said SS broadcasting station including a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent SS broadcasting stations in said hexagonal cellular pattern, each channel signal including navigation beacon data including:

(a) a unique beacon identification,

(b) station latitude and longitude,

(c) time slot frequency and phase characterizations and

(d) selected parameters of adjacent stations.

2. The positioning system defined in claim 1 wherein each said modulator provides a GPS like direct sequence SS signal in which the navigation beacon data is a PN coded broadcast.

3. The positioning system defined in claim 1 including receiver means for receiving the SS signals from at least three of said SS broadcasting stations and determining the location thereof.

4. The positioning system defined in claim 1 in which GPS satellite signals are received in said hexagonal cellular pattern and including means at each said broadcasting station for receiving said GPS satellite signals and deriving therefrom a reference frequency signal and a time epoch signal, said modulator means being adapted to receive said reference frequency and time epoch signals and be timed thereby.

5. Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a hexagonal cellular pattern, each said SS broadcasting station including a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent SS broadcasting stations in said hexagonal cellular pattern, each channel signal including navigation beacon data including:

(a) a unique beacon identification,

(b) station latitude and longitude,

(c) time slot frequency and phase characterizations and

(d) selected parameters of adjacent stations, each said modulator providing a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast, and receiver means for receiving the direct sequence SS signals from at least three of said SS broadcasting stations and determining the location thereof.

6. The positioning system defined in claim 5 in which each said SS broadcasting station includes means to receive GPS satellite signals and means for deriving therefrom a reference frequency signal and a time epoch signal, said modulator means being adapted to receive said reference frequency and time epoch signals and be timed thereby.