Use of doppler direction finding to improve signal link performance in a wireless communication environment

• US 7,409,226 B1
• Filed: 12/29/1999
• Issued: 08/05/2008
• Est. Priority Date: 12/29/1999
• Status: Expired due to Fees

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Stevenson, Carl R.
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): Addy, Anthony S
• Application Number:
  US09/473,650
• Time in Patent Office: 3,142 Days
• Field of Search: 455/562, 455/67.6, 455/154.1, 455/161.1, 455/272, 455/275, 455/276.1, 455/277.1, 455/269, 455/205, 455/226.1, 455227-229, 455/562.1, 455/67.16, 455/404.1, 455/456.1, 342/357.05, 342/368, 342371-372, 342417-418, 342422-423, 342/428, 342432-434, 342436-437, 342/442, 342/443, 342/445
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/01 Reducing phase shift
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24

Abstract

A rotating antenna is used in a wireless system to impart a phase onto a received signal by electronically moving the effective receiving antenna location along a circular path such that the modulation phase angle indicates the bearing of the radio transmission and the gain of a signal transmitted by the antenna is increased in the direction of the received signal to enhance the link between transmitter and receiver. In order to simulate a rotating antenna, the antenna preferably comprises an antenna array having a plurality of antennae for use by one receiver. During reception of a signal from a remote transmitter, a scanner is adapted to scan through the plurality of antennae and in turn provide a signal received from each of the plurality of antennae to the receiver in the wireless system. The signal is modulated by virtue of the antenna rotation to include a Doppler frequency component. Determination of this frequency component enables a receiver to determine the bearing of a received signal and allows the receiver antenna to simulate a highly directional antenna in a transmit mode by operation of the antenna array as a phased array with increased gain in the direction of the received signal.

Claims

1. A wireless communication system, comprising:

a plurality of antennas, configured to operate as a phased array, for use by one receiver;

a scanner adapted to scan through the plurality of antennas to at least substantially eliminate multipath nulls and provide a signal received from each of the plurality of antennas to the receiver and to impart Doppler modulation onto a received signal, wherein one or more of the received signals from the antennas are severely degraded; and

a receiver having direction finding means for determining the bearing of a received signal in accordance with a phase thereof, said received signal containing additional gain,

wherein said receiver is configured to eliminate multipath channel impairments caused at least by the severely degraded signals.

2. A wireless communication system according to claim 1;

wherein a scan rate of the scanner for scanning each of the plurality of antennas is at least 100 hertz.

3. A wireless communication system according to claim 1;

wherein a scan rate of the scanner for the plurality of antennas is at least 2000 hertz.

4. A wireless communication system according to claim 1;

wherein the plurality of antennas are equidistant from a center point.

5. A wireless communication system according to claim 4;

wherein the plurality of antennas are spaced equally apart around a circumference of a circle formed about said center point.

6. A wireless communication system according to claim 1;

wherein the plurality of antennas comprises at least three antennae.

7. A wireless communication system according to claim 1;

wherein the scanner continuously scans and connects each of the plurality of antennae in turn to the receiver for a substantially equal period of time.

8. A method for communication in a wireless communication environment, comprising:

providing a common transceiver with a plurality of antennas configured to operate as a phased array;

continuously scanning through the said plurality of antennas for a substantially fixed period of time by connecting each of the plurality of antennas to a receiver configured to at least substantially eliminate multipath nulls caused at least by severely degraded received signal samples in a substantially stationary wireless communication environment and to impart Doppler modulation onto a received signal;

determining the bearing of the received signal in accordance with a phase thereof, said received signal containing additional gain; and

operating the plurality of antennas as a phased array during a transmit mode.

9. A method for communication in a wireless communication environment according to claim 8;

wherein the wireless communication environment comprises a quasi-stationary wireless communication environment.

10. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment comprises a wireless local area network.

11. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a cordless telephone.

12. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a cordless modem.

13. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a wireless local loop.

14. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a cellular telephone.

15. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a PCS telephone.

16. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a trunked mobile radio system.

17. A method for communication in a wireless communication environment according to claim 9;

wherein the quasi-stationary wireless communication environment is a mobile satellite communications system.

18. A method for communication in a wireless communication environment according to claim 8;

wherein the step of continuously scanning connects each of the plurality of antennas to the receiver at least 100 times per second.

19. A method for communication in a wireless communication environment according to claim 8;

wherein the step of continuously scanning connects each of the plurality of antennas to the receiver at least 2000 times per second.

20. A method for communication in a wireless communication environment according to claim 8;

further comprising the step of locating each of the plurality of antennas substantially equidistant from a center point.

21. A method for communication in a wireless communication environment according to claim 20;

wherein the plurality of antennas are spaced equally apart around a circumference of a circle formed about the center point.