Adaptive beam-steering methods to maximize wireless link budget and reduce delay-spread using multiple transmit and receive antennas

• US 7,982,669 B2
• Filed: 03/26/2010
• Issued: 07/19/2011
• Est. Priority Date: 02/14/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: SiBEAM, Inc. (Lattice Semiconductor Corporation)
• Inventors: Cherniavsky, Dmitry M., Nassiri-Toussi, Karim, Shung, Chuen-Shen, Gilbert, Jeffrey M.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): LIU, HARRY K
• Application Number:
  US12/748,276
• Publication Number:
  US 20100178884A1
• Time in Patent Office: 480 Days
• Field of Search: 342/377
• US Class Current: 342/377
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854

Abstract

A method and apparatus for adaptive beam-steering are disclosed. In one embodiment, the method comprises performing adaptive beam steering using multiple transmit and receive antennas, including iteratively performing a pair of training sequences, wherein the pair of training sequences includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector.

Claims

1. A method comprising:

performing adaptive beam steering using multiple transmit and receive antennas, including iteratively performing a pair of training sequences, wherein the pair of training sequences includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, wherein performing adaptive beam steering using multiple transmit and receive antennas comprises iteratively performing a set of operations, the set of operations including

(a) setting a receive weight vector for receive antennas based on an initial weight vector or phase shift vector;

(b) sequentially measuring channel gains corresponding to each phase to form a first set of channel gains;

(c) calculating a second weight vector based on the first set of channel gains;

(d) setting transmit phase shifts for transmit antennas based on the second weight vector;

(e) sequentially measuring channel gains at the receiver corresponding to each phase to form a second set of channel gains; and

(f) calculating a third weight vector based on the second set of measured channel gains.

2. The method defined in claim 1 wherein iteratively performing the set of operations is performed such that the set of operations is performed four times.

3. A method comprising:

performing adaptive beam steering using multiple transmit and receive antennas, including iteratively performing a pair of training sequences, wherein the pair of training sequences includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, further comprising;

estimating a first channel from a first set of channel gains, wherein calculating a first phase shift vector is based on the estimate of the first channel, wherein estimating the first channel comprises using a unitary matrix as a transfer matrix, such that transmit antenna weight vector is set to a column of the unitary matrix one column at a time; and

estimating a second channel from a second set of channel gains, wherein calculating a second phase shift vector is based on the estimate of the second channel.

4. A method comprising:

performing adaptive beam steering using multiple transmit and receive antennas, including iteratively performing a pair of training sequences, wherein the pair of training sequences includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, further comprising;

estimating a first channel from the first set of channel gains, wherein calculating the second phase shift vector is based on the estimate of the first channel, wherein estimating the first channel comprises using a Hadamard-type matrix as a transfer matrix, such that transmit antenna weight vector is set to a column of the Hadamard-type matrix one column at a time; and

estimating a second channel from the second set of channel gains, wherein calculating the third phase shift vector is based on the estimate of the second channel.

5. A method comprising:

performing adaptive beam steering using multiple transmit and receive antennas, including iteratively performing a pair of training sequences, wherein the pair of training sequences includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, further comprising;

estimating a first channel from a first set of channel gains, wherein calculating a first phase shift vector is based on the estimate of the first channel, wherein estimating the first channel comprises estimating channel vector elements one at a time; and

estimating a second channel from a second set of channel gains, wherein calculating a second phase shift vector is based on the estimate of the second channel.

6. The method defined in claim 5 wherein a number of sequential estimation slots is set to a number, and further wherein the number is 36.

7. The method defined in claim 5 wherein a number of sequential estimation slots is set to a number, and further wherein the number of sequential estimations is greater than the number of different transmit antenna weight vectors, and the transmitter antenna weight vector that produces the strongest received signal at the receiver is repeated more than once.

8. The method defined in claim 5 wherein a number of sequential estimation slots is set to a number, and further wherein the number of sequential estimations is 36, and the transmitter antenna weight vector that produces the strongest received signal at the receiver is repeated 10 times.

9. An apparatus comprising:

a transceiver having a first digital baseband processing unit coupled to a first phased array antenna; and

a receiver having a second digital baseband processing unit coupled to a second phased array antenna, wherein the first and second digital baseband processing units cooperate to perform adaptive beam steering, using multiple transmit and receive antennas, by iteratively performing a pair of trainings, wherein the pair of trainings includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, and wherein said iteratively performing the pair of training sequences includes alternatively changing transmit and receive phase patterns for a plurality of iterations;

wherein the first and second digital baseband processing units cooperate to perform adaptive beam steering by using a set of operations performed iteratively, the set of operations including;

(a) the second digital baseband processing unit setting receive phase shifts for receive antennas of the second phased array antenna based on a first weight vector;

(b) the second digital baseband processing unit causing channel gains corresponding to each phase to be sequentially measured and forming a first set of channel gains;

(c) the second digital baseband processing unit calculating a second weight vector based on the first set of channel gains;

(d) the first digital baseband processing unit setting transmit phase shifts for transmit antennas of the first phased array antenna based on the second weight vector;

(e) the second digital baseband processing unit causing channel gains corresponding to each phase to be measured at the receiver and forming a second set of channel gains; and

(f) the second digital baseband processing unit calculating a third weight vector based on the second set of measured channel gains, wherein the second digital baseband processing unit estimates the first channel by using a unitary matrix as a transfer matrix, such that transmit antenna weight vector is set to columns of the unitary matrix.

10. An apparatus comprising:

a transceiver having a first digital baseband processing unit coupled to a first phased array antenna; and

a receiver having a second digital baseband processing unit coupled to a second phased array antenna, wherein the first and second digital baseband processing units cooperate to perform adaptive beam steering, using multiple transmit and receive antennas, by iteratively performing a pair of trainings, wherein the pair of trainings includes estimating a transmitter antenna-array weight vector and a receiver antenna-array weight vector, and wherein said iteratively performing the pair of training sequences includes alternatively changing transmit and receive phase patterns for a plurality of iterations;

wherein the first and second digital baseband processing units cooperate to perform adaptive beam steering by using a set of operations performed iteratively, the set of operations including

(a) the second digital baseband processing unit setting receive phase shifts for receive antennas of the second phased array antenna based on a first weight vector;

(b) the second digital baseband processing unit causing channel gains corresponding to each phase to be sequentially measured and forming a first set of channel gains;

(c) the second digital baseband processing unit calculating a second weight vector based on the first set of channel gains;

(d) the first digital baseband processing unit setting transmit phase shifts for transmit antennas of the first phased array antenna based on the second weight vector;

(e) the second digital baseband processing unit causing channel gains corresponding to each phase to be measured at the receiver and forming a second set of channel gains; and

(f) the second digital baseband processing unit calculating a third weight vector based on the second set of measured channel gains, wherein the second digital baseband processing unit estimates the first channel by using a Hadamard-type matrix as a transfer matrix, such that transmit antenna weight vector is set to columns of the Hadamard-type matrix.