Method and apparatus for feedback in 3D MIMO wireless systems

• US 8,885,752 B2
• Filed: 12/19/2012
• Issued: 11/11/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc., IN USA, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Intel Corporation
• Inventors: Shirani-Mehr, Hooman, Davydov, Alexei, Fwu, Jong-Kae
• Primary Examiner(s): Torres, Juan A
• Application Number:
  US13/719,343
• Publication Number:
  US 20140029684A1
• Time in Patent Office: 692 Days
• Field of Search: 375/267
• US Class Current: 375/267
• 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. A user equipment (UE) for communication in a multiple-input multiple-output (MIMO) network, the UE comprising:

a channel estimator to estimate channel information based on downlink reference signals received from an evolved Node B (eNodeB);

a vector quantizer to quantize a first portion of the channel information using a codebook;

a scalar quantizer to quantize a second portion of the channel information based on a vertical angle of a radio frequency (RF) beam transmitted by the eNodeB; and

a pre-coding matrix indicator (PMI) module to calculate a PMI vector based on the estimated channel information, the PMI vector comprising coefficients of linear transmit antenna weights for steering the RF beam at the eNodeB in a horizontal direction, and wherein one or more of the coefficients of the PMI vector are multiplied by a vertical phase shift parameter based on steering the RF beam at the eNodeB in to the vertical angle;

wherein the vertical phase shift parameter is of the form;

2. The UE of claim 1, wherein the PMI vector is based on a feedback codebook for three-dimensional (3D) RF beamsteering.

3. The UE of claim 1, wherein the channel estimator is configured to estimate a channel matrix based on the received reference signals, and wherein the PMI module is configured to calculate the PMI vector by performing singular value decomposition (SVD) on the estimated channel matrix and finding a number r of dominant eigenvectors, where the number r is a transmission rank.

4. The UE of claim 1, wherein the PMI module is configured estimate an optimal set of the coefficients and the vertical phase shift parameter.

5. The UE of claim 1, wherein the scalar quantizer is configured to quantize the term:

d_v cos θ

₀

using a scalar quantizer known to both the UE and the eNodeB.

6. The UE of claim 1, wherein the codebook used by the vector quantizer comprises an N_H transmit antenna codebook of a third generation partnership project (3GPP) long term evolution (LTE) or LTE advance (LTE-A) network, where N_H is a number of antennas arranged horizontally in a two-dimensional (2D) antenna array at the eNodeB.

7. The UE of claim 1, wherein the UE is configured to connect to at least one of a wireless local area network (WLAN), a wireless personal area network (WPAN), and a wireless wide area network (WWAN), and the UE includes an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, internal memory, a non-volatile memory port, or combinations thereof.

8. The UE of claim 4, wherein the PMI module is configured to perform a least squares calculation to obtain the estimate.

9. A method for channel information feedback in a multiple-input multiple-output (MIMO) network with three-dimensional beamsteering, the method comprising:

receiving channel information from an evolved Node B (eNodeB);

calculating a first codebook index for a horizontal beamsteering portion of the channel information;

calculating a second codebook index for a vertical beamsteering portion of the channel information, wherein calculating the second codebook index comprises scalar quantization of a parameter associated with a vertical steering angle, and wherein the parameter associated with the vertical steering angle is of the form;

10. The method of claim 9, wherein calculating the first codebook index comprises vector quantization.

11. The method of claim 9, wherein the vector quantization uses an N_H transmit antenna codebook of a third generation partnership project (3GPP) long term evolution (LTE) or LTE advance (LTE-A) network, where N_H is a number of antennas arranged horizontally in a two-dimensional (2D) antenna array at the eNodeB using an LTE codebook.

12. The method of claim 9, where the scalar quantization quantizes the term d_v cos θ

₀.