Wireless device calibration for implicit transmit beamforming

Patent metadata

Field	Value
Publication number	US-9319904-B1
Application number	US-201514875305-A
Country	US
Kind code	B1
Filing date	Oct 5, 2015
Priority date	Sep 29, 2011
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A first sounding packet is transmitted from the wireless communication device to a calibration station. A first channel descriptor is generated based on the first sounding packet. A second sounding packet is transmitted from the calibration station to the wireless communication device. A second channel descriptor is generated based on the second sounding packet. The first channel descriptor and the second channel descriptor are obtained at a processor device. Calibration coefficients indicative of one or both of phase imbalance and amplitude imbalance between a receive radio frequency (RF) chain and a transmit RF chain at the wireless communication device are generated based on the first and the second channel descriptors. The calibration coefficients are sent from the processor device to the wireless communication device.

First claim

What is claimed is:

1. A method of calibrating a wireless communication device, the method comprising:
generating, at a calibration station, a first channel descriptor based on a first sounding packet received, at the calibration station, from the wireless communication device via a first radio frequency (RF) communication channel from the wireless communication device to the calibration station, the first channel descriptor corresponding to the first RF communication channel;
transmitting, with the calibration station, a second sounding packet via a second RF communication channel from the calibration station to the wireless communication device;
obtaining, at a processor device, the first channel descriptor;
obtaining, at the processor device, a second channel descriptor corresponding to the second RF communication channel, wherein
the second channel descriptor was generated, at the wireless communication device, based on the second sounding packet, and
the second channel descriptor was obtained, from the wireless communication device, via a communication link separate from the second RF communication channel;

generating, using the processor device and based on the first channel descriptor and the second channel descriptor, calibration coefficients indicative of one or both of (i) phase imbalance between a receive RF chain and a transmit RF chain at the wireless communication device, and (ii) amplitude imbalance between the receive RF chain and the transmit RF chain at the wireless communication device; and
sending the calibration coefficients from the processor device to the wireless communication device so that the wireless communication device can use the calibration coefficients to compensate for the one or both of (i) the phase imbalance between the receive RF chain and the transmit RF chain, and (ii) the amplitude imbalance between the receive RF chain and the transmit RF chain at the wireless communication device.

2. The method of claim 1 , wherein:
the communication link is a first communication link between the processor device and the wireless communication device; and
obtaining the first channel descriptor comprises obtaining the first channel descriptor via a second communication link between the processor device and the calibration station.

3. The method of claim 1 , wherein:
the communication link is a wired communication link.

4. The method of claim 3 , wherein:
the wired communication link is a first wired communication link between the processor device and the wireless communication device;
sending the calibration coefficients from the processor device to the wireless communication device comprises sending the calibration coefficients via the first wired communication link; and
obtaining the first channel descriptor comprises obtaining the first channel descriptor via a second wired communication link between the processor device and the calibration station.

5. The method of claim 1 , further comprising using the processor device to:
prompt the wireless communication device to transmit the first sounding packet, and
prompt the calibration station to transmit the second sounding packet.

6. The method of claim 1 , further comprising:
receiving the first sounding packet at a vector signal analyzer included in the calibration station.

7. The method of claim 1 , wherein transmitting the second sounding packet from the calibration station comprises transmitting the second sounding packet from a vector signal generator included in the calibration station.

8. The method of claim 1 , wherein the second sounding packet is generated using software, executing on a processor device of a signal generator, that simulates operation of the wireless communication device.

9. The method of claim 1 , wherein the second sounding packet is generated at least by:
using a vector signal analyzer (VSA) to capture a sounding packet transmitted by (i) the wireless communication device or (ii) another wireless communication device;
generating in-phase/quadrature phase (I/Q) samples corresponding to the captured sounding packet; and
generating the sounding packet using the I/Q samples.

10. The method of claim 1 , wherein the second sounding packet is a null data packet (NDP) sounding packet.

11. The method of claim 10 , further comprising:
receiving, at the calibration station, a first NDP announcement (NDPA) packet prior to receiving the first sounding packet; and
transmitting, with the calibration station, a second NDPA packet prior to transmitting the second sounding packet.

12. The method of claim 11 , wherein the second NDPA includes one or both of (i) a medium access control (MAC) address associated with the wireless communication device and (ii) a medium access control (MAC) address associated with the calibration station.

13. The method of claim 1 , wherein:
the communication link is a first wired communication link;
transmitting the first sounding packet comprises transmitting the first sounding packet via a second wired communication link between the wireless communication device and the calibration station; and
transmitting the second sounding packet comprises transmitting the second sounding packet via the second wired communication link.

14. The method of claim 13 , wherein:
the second wired communication link includes a power splitter/combiner unit;
transmitting the first sounding packet via the second wired communication link comprises transmitting the first sounding packet via the power splitter/combiner unit; and
transmitting the second sounding packet via the second wired communication link comprises transmitting the second sounding packet via the power splitter/combiner unit.

15. A calibration system, comprising:
a calibration station configured to:
generate a first channel descriptor based on a first sounding packet received, at the calibration station, from a wireless communication device via a first wireless communication channel from the wireless communication device to the calibration station, the first channel descriptor corresponding to the first wireless communication channel, and
transmit a second sounding packet to the wireless communication device via a second wireless communication channel from the calibration station to the wireless communication device; and

a processor device separate from the wireless communication device, the processor device communicatively coupled to the wireless communication device via a communication link separate from the second wireless communication channel, the processor device configured to
obtain the first channel descriptor,
obtain a second channel descriptor via the communication link, wherein the second channel descriptor was generated by the wireless communication device based on the second sounding packet,
generate, based on the first channel descriptor and the second channel descriptor, calibration coefficients indicative of one or both (i) phase imbalance between a receive radio frequency (RF) chain and a transmit RF chain at the wireless communication device, and (ii) amplitude imbalance between the receive RF chain and the transmit RF chain at the wireless communication device, and
send the calibration coefficients from the controller to the wireless communication device so that the wireless communication device can use the calibration coefficients to compensate for the one or both of (i) the phase imbalance between the receive RF chain and the transmit RF chain, and (ii) the amplitude imbalance between the receive RF chain and the transmit RF chain at the wireless communication device.

Assignees

• Marvell Int Ltd

Inventors

• Srinivasa Sudhir
• Zheng Xiayu
• Zhang Hongyuan
• Nabar Rohit U
• Madani Riddhi
• Salhotra Atul
• Heinke Erik
• Bosso Brian

Classifications

• H04W24/02 Primary

  Arrangements for optimising operational condition · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04L43/12

  Network monitoring probes · CPC title

• H04B17/14 Primary

  of the whole transmission and reception path, e.g. self-test loop-back · CPC title

• H04W24/00

  Supervisory, monitoring or testing arrangements · CPC title