Csi feedback for mimo wireless communication systems with polarized active antenna array

Patent metadata

Field	Value
Publication number	US-2016157218-A1
Application number	US-201514874216-A
Country	US
Kind code	A1
Filing date	Oct 2, 2015
Priority date	Nov 17, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

A base station capable of communicating with a user equipment (UE) includes a transceiver configured to transmit 8-port Channel State Information-Reference Signal (CSI-RS) according to a CSI-RS configuration for the UE, and downlink signals containing the CSI-RS configuration on physical downlink shared channels (PDSCH), and receive, from the UE, uplink signals containing Precoder Matrix Indicator (PMI) derived using the 8-port CSI-RS, and a controller configured to convert the PMI to one of predetermined precoding vectors. A user equipment includes a transceiver configured to receive downlink signals containing a CSI-RS configuration on PDSCH transmitted by the BS, and 8-port CSI-RS according to the CSI-RS configuration, and transmit uplink signals containing a PMI, a controller configured to decode the CSI-RS configuration from the downlink signals, and derive the PMI by utilizing channel estimates based on the 8-port CSI-RS, the PMI mapped to one of precoding vectors.

First claim

What is claimed:

1 . A base station capable of communicating with a user equipment (UE), the base station comprising:
a transceiver configured to:
transmit
8-port Channel State Information-Reference Signal (CSI-RS) according to a CSI-RS configuration for the UE; and
downlink signals containing the CSI-RS configuration on physical downlink shared channels (PDSCH); and

receive, from the UE, uplink signals containing a precoding matrix indicator (PMI) derived using the 8-port CSI-RS; and
a controller configured to convert the PMI to one of predetermined precoding vectors including

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2 . The base station of claim 1 , wherein two CSI-RS on antenna ports 15 and 19 among the 8-port CSI-RS are respectively mapped onto a first and a second groups of a same number of antenna elements with substantially similar beamforming weight vectors being applied,
wherein an antenna element on the first group is polarized according to a first angle, an antenna element on the second group is polarized according to a second angle, and the two antenna elements on the first and the second groups are on a same physical location comprising a dual-polarized pair, and wherein the difference between the first and the second angles is substantially equal to 90 degrees.

3 . The base station of claim 1 , wherein each of the 8-port CSI-RS is beamformed with a beamforming weight vector estimated with sounding reference signals (SRS) transmitted by the UE.

4 . The base station of claim 1 , wherein the CSI-RS is beamformed with a beamforming weight vector, and wherein the controller is further configured to derive the beamforming weight vector by processing a precoding vector reported by the UE.

5 . The base station of claim 4 , wherein the transceiver is further configured to:
transmit
downlink signals containing a second CSI-RS configuration on PDSCH, and
N-port CSI-RS according to the second CSI-RS configuration, the Nbeing a positive integer; and
receive, from the UE, uplink signals containing a second PMI comprising a nonnegative integer derived using the N-port CSI-RS; and wherein the controller is further configured to determine the precoding vector as an oversampled DFT vector according to the second PMI.

6 . The base station of claim 4 , wherein the transceiver is further configured to:
transmit
downlink signals containing a second CSI-RS configuration on PDSCH,
the N-port CSI-RS according to the second CSI-RS configuration; and
receive uplink signals from the UE containing the second PMI comprising two nonnegative integers derived using the N-port CSI-RS, and wherein the controller is further configured to determine the precoding vector as a Kronecker product of two oversampled DFT vectors corresponding to the second PMI.

7 . The base station of claim 6 ,
wherein the N-port CSI-RS are mapped to a 2-dimensional array of N transceiver units respectively mapped to N antenna subarrays placed on a 2-dimensional antenna panel.

8 . A method for communicating with a user equipment (UE), the method comprising:
transmitting
8-port Channel State Information-Reference Signal (CSI-RS) according to a CSI-RS configuration for the UE; and
downlink signals containing the CSI-RS configuration on physical downlink shared channels (PDSCH); and
receiving, from the UE, uplink signals containing a precoding matrix indicator (PMI) derived using the 8-port CSI-RS; and converting the PMI to one of predetermined precoding vectors including

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9 . The method station of claim 8 ,
wherein two CSI-RS on antenna ports 15 and 19 among the 8-port CSI-RS are respectively mapped onto a first and a second groups of a same number of antenna elements with substantially similar beamforming weight vectors being applied, wherein an antenna element on the first group is polarized according to a firs

Assignees

• Samsung Electronics Co Ltd

Inventors

• Nam Young-Han
• Li Yang
• Onggosanusi Eko

Classifications

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04B7/0617

  for beam forming · CPC title

• H04B7/0456

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title

• H04B7/0639

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title