Beamforming

• US 9,942,931 B2
• Filed: 02/24/2014
• Issued: 04/10/2018
• Est. Priority Date: 08/01/2013
• Status: Active Grant

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: Fujitsu Limited
• Inventors: Zhu, Chenxi, Ito, Akira
• Primary Examiner(s): NG, CHRISTINE Y
• Application Number:
  US14/908,980
• Publication Number:
  US 20160173177A1
• Time in Patent Office: 1,506 Days
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 8/186 Processing of subscriber group data

Abstract

A method of beamforming a transmission from an antenna array having rows of antenna elements and columns of antenna elements may include determining a first precoding matrix associated with a first orientation. The method may further include determining a second precoding matrix associated with a second orientation. The method may further include transmitting a transmission having beamforming based at least in part on the first precoding matrix and based at least in part on the second precoding matrix.

Claims

1. A method of beamforming a transmission from an array antenna including rows of antenna elements and columns of antenna elements, the method comprising:

determining a first precoding matrix associated with a first orientation;

determining a second precoding matrix associated with a second orientation;

transmitting a transmission including beamforming based at least in part on the first precoding matrix and based at least in part on the second precoding matrix;

transmitting first reference symbols; and

transmitting second reference symbols different from the first reference symbols, including beamforming based at least in part on the first precoding matrix,

wherein;

determining the first precoding matrix is based at least in part on a first feedback received in response to transmitting a first set of reference symbols; and

determining the second precoding matrix is based at least in part on a second feedback received in response to transmitting a second set of reference symbols different from the first set of reference symbols, the second feedback based at least in part on a predefined one-dimensional beamforming codebook.

2. The method of claim 1, wherein:

the first precoding matrix includes a vertical precoding matrix;

the first orientation is associated with a column orientation of the columns of antenna elements;

the second precoding matrix includes a horizontal precoding matrix; and

the second orientation is associated with a row orientation of the rows of antenna elements.

3. The method of claim 1, wherein transmitting the first set of reference symbols includes transmitting the first reference symbols from one of the columns of antenna elements.

4. The method of claim 1, the method further comprising transmitting an indicator that the first feedback is to be based on the first reference symbols over a period of time, wherein transmitting the first reference symbols includes transmitting the first reference symbols from more than one of the columns of antenna elements over the period of time.

5. The method of claim 1, wherein the first feedback includes a first precoding-matrix identifier (PMI).

6. The method of claim 1, wherein the first feedback is based at least in part on a pre-defined rank-1 codebook.

7. The method of claim 1, wherein the first feedback is based at least in part on a codebook based on discrete Fourier transform (DFT).

8. The method of claim 1, further comprising determining a channel matrix.

9. The method of claim 8, further comprising estimating a composite channel including the first precoding matrix and the channel matrix.

10. The method of claim 1, wherein the transmission includes a physical downlink shared channel (PDSCH) transmission including demodulation reference signals (DM-RS), the DM-RS having beamforming based at least in part on the first precoding matrix and based at least in part on the second precoding matrix.

11. A base station comprising:

an array antenna including rows of antenna elements and columns of antenna elements; and

a non-transitory computer-readable medium having encoded therein programming code executable by a processor to perform operations of beamforming a transmission from the array antenna, the operations comprising;

determining a first precoding matrix associated with a first orientation;

determining a second precoding matrix associated with a second orientation;

transmitting the transmission including beamforming based at least in part on the first precoding matrix and based at least in part on the second precoding matrix;

transmitting first reference symbols; and

transmitting second reference symbols different from the first reference symbols, including beamforming based at least in part on the first precoding matrix,

wherein;

determining the first precoding matrix is based at least in part on a first feedback received in response to transmitting a first set of reference symbols; and

determining the second precoding matrix is based at least in part on a second feedback received in response to transmitting a second set of reference symbols different from the first set of reference symbols, the second feedback based at least in part on a predefined one-dimensional beamforming codebook.

12. The base station of claim 11, wherein:

the first precoding matrix includes a vertical precoding matrix;

the first orientation is associated with a column orientation of the columns of antenna elements;

the second precoding matrix includes a horizontal precoding matrix; and

the second orientation is associated with a row orientation of the rows of antenna elements.

13. The base station of claim 11, wherein transmitting the first set of reference symbols includes transmitting the first reference symbols from one of the columns of antenna elements.

14. The base station of claim 11, wherein:

transmitting the first reference symbols includes transmitting the first reference symbols from more than one of the columns of antenna elements over a period of time; and

the operations further comprise transmitting an indicator that the first feedback is to be based on the first reference symbols over the period of time.