Method for efficient channel estimation and beamforming in FDD system by exploiting uplink-downlink correspondence

• US 10,588,126 B2
• Filed: 11/06/2017
• Issued: 03/10/2020
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Xue, Feng, Li, Qinghua, Zhu, Yuan
• Primary Examiner(s): Truong, Lan-Huong
• Application Number:
  US15/804,360
• Publication Number:
  US 20180110049A1
• Time in Patent Office: 855 Days
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 25/021 Estimation of channel covariance
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/03891 Spatial equalizers MIMO diversity systems H04B7/0413
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 68/04 multi-step notification using statistical or historical mobility data
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/004 : in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 : in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0816 : with collision avoidance
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/19 : Connection re-establishment
• CPC Class Codes: H04W 76/30 : Connection release
• CPC Class Codes: H04W 8/005 : Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/045 : using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method for selecting at least one parameter for downlink data transmission with a mobile user equipment. The method is executable by a wireless communication base station having multiple antennas configured to communicate wirelessly with the mobile user equipment. The method receives an uplink probing signal from the mobile user equipment. The method determines a plurality of angles of arrival for a corresponding plurality of paths between the mobile user equipment and the multiple antennas. The method transmits a plurality of downlink probing signals directionally toward corresponding angles of arrival in the plurality of angles of arrival. Each downlink probing signal is a virtual antenna port with respect to the mobile user equipment. The method receives channel state information. The method composes at least one of a rank indicator (RI), precoding matrix indicator (PMI), or modulating and coding scheme (MCS) for downlink data transmission to the mobile user equipment.

Claims

1. An apparatus of a wireless device, the apparatus comprising:

processing circuitry, the processing circuitry configured to;

decode a first probing signal from a second wireless device, the first probing signal received via a plurality of communication paths;

in response to receiving the first probing signal, determine a plurality of signal measurements associated with the plurality of communication paths between the wireless device and the second wireless device, wherein each signal measurement of the plurality of signal measurements is associated with a corresponding one of the plurality of communication paths and is determined based on a spatial signature of the corresponding one of the plurality of paths; and

encode a plurality of second probing signals for transmission to the second wireless device, each probing signal of the plurality of second probing signals encoded for directional transmission to the second wireless device on the corresponding one of the plurality of communication paths, based on the plurality of signal measurements, and wherein the first probing signal and the plurality of second probing signals are configured as beamforming vectors.

2. The apparatus of claim 1, wherein the processing circuitry is further configured to:

configure each probing signal of the plurality of second probing signals as a virtual antenna port with respect to the second wireless device.

3. The apparatus of claim 2, wherein the processing circuitry is further configured to:

configure each virtual antenna port based on a discrete Fourier transform (DFT) vector.

4. The apparatus of claim 1, wherein the plurality of signal measurements comprises a plurality of angles-of-arrival corresponding to the plurality of communication paths.

5. The apparatus of claim 4, wherein the processing circuitry is further configured to:

determine each of the plurality of angles of arrival based on projecting the received first probing signal towards the spatial signature of the corresponding one of the plurality of paths.

6. The apparatus of claim 1, further comprising:

transceiver circuitry coupled to the processing circuitry; and

a plurality of antennas coupled to the transceiver circuitry.

7. The apparatus of claim 6, wherein each antenna of the plurality of antennas receives the first probing signal via the corresponding one of the plurality of communication paths.

8. The apparatus of claim 1, wherein to determine the plurality of signal measurements associated with the plurality of communication paths between the wireless device and the second wireless device, the processing circuitry is further configured to:

employ an angle-of-arrival estimation algorithm.

9. The apparatus of claim 8, wherein based on the angle-of-arrival estimation algorithm, the processing circuitry is further configured to:

project the received first probing signal toward different spatial signatures spanning an angular space;

determine peak values from the projection; and

adopt the peak values as estimated angles-of-arrival for the plurality of signal measurements.

10. An apparatus of a wireless device, the apparatus comprising:

processing circuitry, the processing circuitry configured to;

decode a first probing signal from a second wireless device, the first probing signal received via a plurality of communication paths;

in response to receiving the first probing signal, determine a plurality of signal measurements associated with the plurality of communication paths between the wireless device and the second wireless device, wherein each signal measurement of the plurality of signal measurements is associated with a corresponding one of the plurality of communication paths; and

encode a plurality of second probing signals for transmission to the second wireless device, each probing signal of the plurality of second probing signals encoded for directional transmission to the second wireless device on the corresponding one of the plurality of communication paths, based on the plurality of signal measurements;

decode channel state information received from the second wireless device, the channel state information corresponding to a channel associated with one of the plurality of second probing signals; and

encode;

in response to the received channel state information, a rank indicator (RI) and a precoding matrix indicator (PMI) for transmission to the second wireless device.

11. The apparatus of claim 10, wherein the processing circuitry is further configured to:

compose, in response to the received channel state information, a modulating and coding scheme (MCS) for transmission to the second wireless device, wherein each of the plurality of second probing signals appears to originate from a different location from a point of view of the second wireless device.

12. An apparatus of a mobile communication device, the apparatus comprising:

processing circuitry coupled to memory, the processing circuitry configured to;

encode for transmission to a base station (BS), a plurality of channel sounding signals;

estimate a plurality of angles-of-arrival for a corresponding plurality of paths between the mobile communication device and multiple antennas of the BS based on the channel sounding signals, wherein each of the angles-of-arrival is associated with a corresponding one of the plurality of paths between the mobile communication device and the BS;

decode a plurality of downlink probing signals received from the multiple antennas of the BS, each downlink probing signal being transmitted directionally toward a corresponding angle-of-arrival of the plurality of the angles-of-arrival, each downlink probing signal being a virtual antenna port with respect to the mobile communication device;

encode channel state information for transmission to the BS, the channel state information corresponding to a channel associated with one of the downlink probing signals; and

decode a rank indicator (RI) and a precoding matrix indicator (PMI) for a downlink data transmission from the BS, the RI and the PMI in response to the channel state information.

13. The apparatus of claim 12, wherein the processing circuitry is further configured to:

determine each of the angles-of-arrival based on projecting the channel sounding signals towards a spatial signature of the corresponding one of the plurality of paths.

14. The apparatus of claim 12, wherein the channel sounding signals and the downlink probing signals are at different frequencies.

15. The apparatus of claim 12, wherein the processing circuitry is further configured to:

decode a modulating and coding scheme (MCS) for the downlink data transmission from the BS in response to the channel state information, wherein each downlink probing signal appears to originate from a different location from a point of view of the mobile communication device.

16. The apparatus of claim 12, wherein the processing circuitry is further configured to:

encode the plurality of channel sounding signals for transmission to the BS via a plurality of transmit antennas in a pre-determined manner.