METHOD AND APPARATUS FOR GENERATING REFERENCE SIGNAL IN ANALOG/DIGITAL MIXED BF SYSTEM

• US 20170111149A1
• Filed: 12/24/2016
• Published: 04/20/2017
• Est. Priority Date: 03/29/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Tae-Young, Han, Shuangfeng, Park, Jeong-Ho
• Granted Patent: US 10,320,540 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A millimeter radio wave communication system. In a method for operating a base station (BS) in an analog/digital mixed BF system, an analog BF direction is determined. A digital BF precoder is determined for the determined analog BF direction. Digital BF precoding is performed using the digital BF precoder with respect to the determined analog BF direction. A DownLink Reference Signal (DL RS) is transmitted in the analog BF direction on which the digital BF precoding has been performed.

Claims

1. An apparatus for a transmitter in a wireless system, the apparatus comprising:

a digital beamforming unit configured to generate precoded signals by precoding a plurality of downlink reference signals (DL RSs);

a plurality of radio frequency (RF) chains coupled to the digital beamforming unit, the plurality of RF chains are configured to determine a direction of each of the precoded signals;

a plurality of antenna elements subsets respectively coupled to each of the plurality of RF chains, the plurality of antenna elements subsets are configured to transmit the precoded signals based on the determined direction,

wherein the precoded signals are transmitted through a plurality of subcarriers in the determined direction.

2. The apparatus of claim 1, wherein each of the plurality of RF chains comprises a phase shifter configured to determine the direction of each of the precoded signals by modifying phases of each of the precoded signals.

3. The apparatus of claim 1, further comprising:

at least one processor configured to;

determine an analog direction of each of the plurality of DL RSs before the precoded signals are generated; and

generate the precoded signals by precoding each of the plurality of DL RSs based on the determined analog direction.

4. The apparatus of claim 3, wherein the at least one processor is further configured to:

apply a power boost factor to each of the plurality of DL RSs; and

transmit information for the applied power boost factor.

5. The apparatus of claim 1, wherein the plurality of antenna elements subsets are further configured to receive feedback information for channel estimation performed by using the transmitted precoded signals

6. An apparatus for a receiver in a wireless system, the apparatus comprising:

a plurality of antenna elements subsets configured to receive a plurality of downlink reference signals (DL RSs);

a plurality of radio frequency (RF) chains respectively coupled to each of the plurality of antenna elements subsets, the plurality of RF chains are configured to determine a direction of each of the plurality of DL RSs;

a digital beamforming unit coupled to the plurality of RF chains, the digital beamforming unit is configured to perform post precoding for each of the plurality of DL RSs,

wherein the plurality of DL RSs are received through a plurality of subcarriers in the pre-determined direction.

7. The apparatus of claim 6, wherein each of the plurality of RF chains comprises a phase shifter configured to determine the direction of each of the plurality of DL RSs by modifying phases of each of the plurality of DL RSs.

8. The apparatus of claim 6, further comprising at least one processor configured to:

perform channel estimation using the plurality of DL RSs; and

transmit feedback information for the channel estimation.

9. The apparatus of claim 8, wherein the feedback information comprises a direction of a DL RS among the plurality of DL RSs.

10. The apparatus of claim 6, wherein the plurality of antenna subsets are further configured to receive information for a power boost factor applied to each of the plurality of DL RSs.