Systems and methods for calibrating transmission of an antenna array

• US 20060058022A1
• Filed: 08/29/2005
• Published: 03/16/2006
• Est. Priority Date: 08/27/2004
• Status: Abandoned Application

• Current Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Webster, Mark, Shearer, Daniel, Halford, Steven, Cochran, Bruce
• Application Number:
  US11/215,563
• Publication Number:
  US 20060058022A1
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Disclosed herein are various embodiments of methods, systems, and apparatuses for sending and receiving signals in a digital communication system. In one embodiment performs steps of transmitting a signal from a device with a first antenna array and calibrating the signal with a phase shift of the signal. In one exemplary method embodiment, a signal is transmitted from a beam-forming transmitter to an assisting receiver in an IEEE 802.11 wireless transmission. A return calibration signal from the assisting receiver with information regarding the phase error of signal is received by the beam-forming transceiver. The beam-forming transmitter introduces a calibration phase error to cancel the phase error as reported by the assisting receiver.

Claims

1. A method of communications comprising:

transmitting a signal from a device with a first antenna array; and

calibrating the signal with a phase shift of the signal.

2. The method of claim 1, further comprising:

receiving a calibration signal;

wherein calibrating with a phase shift of the first antenna array is based at least in part on the received calibration signal.

3. The method of claim 2, wherein the calibration signal is received in a preamble of a signal modulated using Orthogonal Frequency Divisional Multiplexing (OFDM).

4. The method of claim 1, further comprising:

periodically recalibrating with a phase shift of the signal if the device receives an incoming signal on a second antenna array that is separate from the first antenna array.

5. A method for managing wireless local area network (LAN) communications comprising:

defining an OFDM signal pattern of subcarriers comprising a preamble training structure, the preamble training structure comprising a sync pattern including a calibration symbol for calibrating with a phase shift of a signal and a data pattern; and

transmitting the signal pattern.

6. The method of claim 5, wherein the sync pattern including the calibration symbol is a long sync pattern.

7. The method of claim 5, wherein the subcarriers are demultiplexed sequentially to a plurality of transmit antennas.

8. A wireless radio comprising:

an array of antennas; and

a processor configured to prepare a signal for transmission using the array of antennas and to calibrate with a phase shift of the signal.

9. The radio of claim 8, wherein the array of antennas comprises directional antennas for directing the transmission of the signal to a receiver.

10. The radio of claim 8, wherein the processor is further configured to:

receive a calibration signal; and

calibrate with a phase shift of the signal based at least in part on the received calibration signal.

11. The radio of claim 10, wherein the processor is configured to receive the calibration signal in a preamble of a signal modulated using Orthogonal Frequency Divisional Multiplexing (OFDM).

12. The radio of claim 8, wherein at least one antenna of the array of antennas both transmits signals and receives signals.

13. The radio of claim 8, wherein at least one antenna of the array of antennas either transmits signals or receives signals.

14. The radio of claim 8, wherein the processor is further configured to periodically recalibrate the phase shift of the signal.

15. A system for wireless local area network communications comprising:

an array of antennas; and

a processor configured to prepare a signal for transmission using the array of antennas and to calibrate with a phase shift of the signal.

16. The system of claim 15, wherein the antennas of the array comprise directional antennas for directing the transmission of a signal to a receiver.

17. The system of claim 15, wherein the processor is further configured to:

receive a calibration signal; and

calibrate with a phase shift of the signal corresponding to the received calibration signal.

18. The system of claim 17, wherein the processor is configured to receive the calibration signal in a preamble of a signal modulated using Orthogonal Frequency Divisional Multiplexing (OFDM).

19. The system of claim 15, wherein an antenna of the array of antennas both transmits signals and receives signals.

20. The system of claim 15, wherein an antenna of the array of antennas either transmits signals or receives signals.

21. The radio of claim 15, wherein the processor is further configured to periodically recalibrate the phase shift of the signal.