Method and apparatus for feedback in 3D MIMO wireless systems

• US 9,344,170 B2
• Filed: 10/10/2014
• Issued: 05/17/2016
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Shirani-Mehr, Hooman, Davydov, Alexei, Fwu, Jong-Kae
• Primary Examiner(s): Torres, Juan A
• Application Number:
  US14/511,792
• Publication Number:
  US 20150139121A1
• Time in Patent Office: 585 Days
• Field of Search: 375/295
• US Class Current: 1/1
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/046 taking physical layer constraints into account
• CPC Class Codes: H04B 7/0469 taking special antenna structures, e.g. cross polarized antennas into account
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• 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: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1864 ARQ related signaling H04L1/1607 takes precedence
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• 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 88/08 : Access point devices

Abstract

Systems and methods provide channel state information feedback in a multiple-input multiple-output (MIMO) system. A method quantizes a pre-coding matrix indicator (PMI) and feeds it back from a user equipment (UE) to an evolved Node B (eNodeB). The method may use codebooks for vector quantization of optimal horizontal direction and a scalar quantizer to quantize an optimal vertical direction from the eNodeB to a selected UE.

Claims

1. An evolved Node B (eNodeB), comprising:

a two-dimensional (2D) antenna array for three-dimensional (3D) steering of a radio frequency (RF) beam toward a first user equipment (UE);

a scalar dequantizer to dequantize a first feedback indicator received from the first UE to determine vertical phase shift parameters to apply to respective rows of the antennas in the 2D antenna array for steering the RF beam in a vertical direction;

a vector dequantizer to dequantize a second feedback indicator received from the first UE to determine coefficients of linear transmit antenna weights to apply to respective columns of antennas in the 2D antenna array for steering the RF beam in a horizontal direction;

a pre-coding matrix indicator (PMI) reconstructor to calculate a PMI vector comprising the coefficients multiplied by the vertical phase shift parameters;

a precoder to, in a multi-user multiple-input multiple-output (MIMO) mode;

combine the calculated PMI vector with one or more reconstructed PMI vectors corresponding to one or more second UEs, respectively;

calculate, using the combination, a pre-coding matrix based on a beamforming scheme to reduce interference between the first UE and the one or more second UEs; and

use the calculated pre-coding matrix to pre-code downlink data; and

a transmitter to transmit the pre-coded downlink data to the first UE.

2. The eNodeB of claim 1, wherein the vector dequantizer uses a codebook known to the eNodeB and the first UE to dequantize the coefficients.

3. The eNodeB of claim 1, wherein the precoder, in a single-user MIMO mode, is configured to use the calculated PMI vector to generate the pre-coded downlink data.

4. A method for an evolved Node B (eNodeB), the method comprising:

performing scalar dequantization to dequantize a first feedback indicator received from a first user equipment (UE) to determine vertical phase shift parameters to apply to respective rows of antennas in a two-dimensional (2D) antenna array for steering a radio frequency (RF) beam in a vertical direction;

performing vector dequantization to dequantize a second feedback indicator received from the first UE to determine coefficients of linear transmit antenna weights to apply to respective columns of antennas in the 2D antenna array for steering the RF beam in a horizontal direction;

calculating a pre-coding matrix indicator (PMI) vector comprising the coefficients multiplied by the vertical phase shift parameters;

in a multi-user multiple-input multiple-output (MIMO) mode;

combining the calculated PMI vector with one or more reconstructed PMI vectors corresponding to one or more second UEs, respectively;

calculating, using the combination, a pre-coding matrix based on a beamforming scheme to reduce interference between the first UE and the one or more second UEs; and

using the calculated pre-coding matrix to pre-code downlink data; and

transmitting the pre-coded downlink data to the first UE.

5. The method claim 4, wherein performing the vector dequantization comprises using a codebook known to the eNodeB and the first UE to dequantize the coefficients.

6. The method of claim 4, in a single-user MIMO mode, using the calculated PMI vector to generate the pre-coded downlink data.

7. At least one non-transitory computer-readable storage medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

scalar dequantization to dequantize a first feedback indicator received from a first user equipment (UE) to determine vertical phase shift parameters to apply to respective rows of antennas in a two-dimensional (2D) antenna array for steering a radio frequency (RF) beam in a vertical direction;

vector dequantization to dequantize a second feedback indicator received from the first UE to determine coefficients of linear transmit antenna weights to apply to respective columns of antennas in the 2D antenna array for steering the RF beam in a horizontal direction;

calculate a pre-coding matrix indicator (PMI) vector comprising the coefficients multiplied by the vertical phase shift parameters;

in a multi-user multiple-input multiple-output (MIMO) mode;

combine the calculated PMI vector with one or more reconstructed PMI vectors corresponding to one or more second UEs, respectively;

calculate, using the combination, a pre-coding matrix based on a beamforming scheme to reduce interference between the first UE and the one or more second UEs; and

use the calculated pre-coding matrix to pre-code downlink data; and

transmit the pre-coded downlink data to the first UE.

8. The at least one non-transitory computer-readable storage medium claim 7, wherein to perform the vector dequantization, the operations further use a codebook known to the eNodeB and the first UE to dequantize the coefficients.

9. The at least one non-transitory computer-readable storage medium of claim 7, in a single-user MIMO mode, the operations further use the calculated PMI vector to generate the pre-coded downlink data.