Phase agile antenna for use in position determination

• US 6,148,195 A
• Filed: 02/17/1998
• Issued: 11/14/2000
• Est. Priority Date: 02/18/1997
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Schuchman, Leonard, Engelbrecht, Lloyd
• Primary Examiner(s): Hunter, Daniel S.
• Assistant Examiner(s): WYCHE, MYRON
• Application Number:
  US09/025,093
• Time in Patent Office: 1,001 Days
• Field of Search: 455/562, 455/456, 455/422, 455/457, 455/561, 455/424
• US Class Current: 455/424
• CPC Class Codes: G01S 3/16 using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 3/52 using a receiving antenna moving, or appearing to move, in a cyclic path to produce a Doppler variation of frequency of the received signal
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays

Abstract

A cellular telephone communication system has at least one base station and a plurality of remote mobile stations in which both base and mobile stations have RF transceivers which communicate with each other using periodically repeated pulse sequence epochs whose time patterns are known at both transmitting and receiving station. Each mobile station transceiver, during normal operation, establishes and maintains synchronization between the start of a received pulse epoch at the mobile station and a subsequent beginning of a responsive transmitted pulse epoch. An agile antenna system is located at the base station and includes at least one scanning antenna spaced a selected distance from a central reference point. The scanning antenna is effectively rotated relative to the central reference point and adapted to receive RF transmissions from a selected mobile station, and a direction or bearing detection processor is connected to antenna systems for detecting from received RF transmissions from the selected mobile station the bearing to the selected mobile station from the base station. The bearing sensing processor is one selected from amplitude sensing, phase sensing or frequency sensing or a combination of these sensing principles. A range measuring processor circuit also at the base station measures the time interval from the start of the base station'"'"'s transmitted pulse epoch to the start of a pulse epoch subsequently received from the selected mobile station and derives range to the selected mobile station therefrom.

Claims

1. In a cellular telephone communication system having at least one base station and a plurality of remote mobile stations in which both base and mobile stations have RF transceivers which communicate with each other using periodically repeated pulse sequence epochs whose time patterns are known at both transmitting and receiving station, each mobile station transceiver, during normal operation, establishes and maintains synchronization between the start of a received pulse epoch at the mobile station and a subsequent beginning of a responsive transmitted pulse epoch, the improvement comprising:

an agile antenna system at said base station, said agile antenna system including at least one scanning antenna spaced a predetermined distance from a reference point, said at least one scanning antenna being effectively rotated relative to the central reference point and adapted to receive RF transmissions from a selected mobile station, and a direction detection processor connected to said at least one scanning antenna for detecting from received RF transmissions from said selected mobile station the bearing to said selected mobile station from said base station, and

a range measuring processor at said base station for measuring the time interval from the start of said base station'"'"'s transmitted pulse epoch to the start of a pulse epoch subsequently received from the selected mobile station and deriving range to said selected mobile station therefrom.

2. The cellular telephone communication system defined in claim 1 where in said direction detecting processor is one selected from amplitude sensing, frequency sensing and phase sensing.

4. The cellular telephone communication system defined in claim 2 where in said bearing sensing processor is one selected from amplitude sensing, frequency sensing and phase sensing.

3. In a cellular telephone communication system having at least one base station and a plurality of remote mobile stations in which both base and mobile stations have RF transceivers which communicate with each other using periodically repeated pulse sequence epochs whose time patterns are known at both transmitting and receiving station, each mobile station transceiver, during normal operation, establishes and maintains synchronization between the start of a received pulse epoch at the mobile station and a subsequent beginning of a responsive transmitted pulse epoch, the improvement comprising:

an agile antenna system at said base station, said agile antenna system including a central reference antenna and at least one scanning antenna spaced a predetermined distance from said reference antenna, said at least one scanning antenna being effectively rotated relative to said reference antenna, and a receiving system, including a bearing detection processor connected to said antennas for detecting the bearing to a selected mobile station from said base station, and

a range measuring processor at said base station for measuring the time interval from the start of said base station'"'"'s transmitted pulse epoch to the start of a pulse epoch subsequently received from the selected mobile station and deriving range to said selected mobile station therefrom.

5. A position location system for an RF communication system in which at least one base station has a communication receiver with a reference antenna for use with mobile stations, each mobile station having an RF transceiver for communicating with said base station using repeated pulse sequence epochs whose time patterns are known at both transmitting and receiving station, each mobile station transceiver, during normal operation, being equipped to establish and maintain synchronization between the start of a received epoch at the mobile station and a subsequent beginning of a reference to a responsive transmitted pulse epoch, an agile antenna system at said base station including at least one scanning antenna spaced a predetermined distance from said reference antenna, said at least one scanning antenna being effectively rotated relative to the central reference antenna and adapted to receive RF transmissions from at least one selected mobile station, and a bearing sensing processor connected to the at least one scanning antenna for detecting from received RF transmissions from the selected mobile station the bearing to the selected mobile station from said base station, and

a range measuring processor at said base station for measuring the time interval between the start of said base station'"'"'s transmitted pulse epoch to the start of a pulse epoch subsequently received from the selected mobile station and deriving range to said selected mobile station therefrom.

6. The system defined in claim 5 wherein said bearing sensing processor is selected from amplitude sensing, frequency sensing, and phase sensing.

7. In an RF communication system having a central reference antenna and an array of antenna positions around the reference antenna for receiving digital telephony radio signals from a plurality of mobile sources, detecting the relative phases of the radio signals received at said reference antenna and each of said antenna positions in said circular array, and deriving therefrom the direction to each said mobile source relative to said reference antenna.