Method and Apparatus For Transmitting Common Signal In Hybrid Beamforming

Patent metadata

Field	Value
Publication number	US-2016182138-A1
Application number	US-201514974003-A
Country	US
Kind code	A1
Filing date	Dec 18, 2015
Priority date	Dec 19, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

The present disclosure provides a method and apparatus for transmitting a common signal in hybrid beamforming. The method includes: acquiring an analog common signal to be transmitted; selecting a different codeword for each RF chain from a codebook for analog beamforming and obtaining an analog beamformer; beamforming the analog common signal to be transmitted in each RF chain according to the analog beamformer; and transmitting the beamformed analog common signal in each RF chain.

First claim

What is claimed is:

1 . A method for transmitting a common signal in hybrid beamforming, comprising:
acquiring an analog common signal to be transmitted; selecting a different codeword for each RF chain from a codebook for analog beamforming and obtaining an analog beamformer; beamforming the analog common signal to be transmitted in each RF chain according to the analog beamformer; and transmitting the beamformed analog common signal in each RF chain.

2 . The method of claim 1 , further comprising:
dividing codewords in the codebook for analog beamforming into at least two codeword groups, wherein each codeword group includes at least one codeword; wherein selecting a different codeword for each RF chain from the codebook for analog beamforming and obtaining the analog beamformer comprises: selecting different codeword groups for adjacent timeslots, selecting a different codeword from the selected codeword group for each RF chain and obtaining an analog beamformer.

3 . The method of claim 2 , wherein codewords in the codebook for analog beamforming are divided into at least two codeword groups according to users' distribution.

4 . The method of claim 1 , before acquiring the analog common signal to be transmitted, further comprising:
acquiring a digital common signal for generating the analog common signal to be transmitted; acquiring a cyclic shift for each RF chain according to a principle of using different cyclic shifts for RF chains corresponding to adjacent beams, and generating a digital beamformer using the acquired cyclic shift; beamforming the digital common signal in each RF chain using the digital beamformer in digital baseband.

5 . The method of claim 4 , further comprising:
calculating the cyclic shift according to a maximum multipath delay spread of a channel impulse response and a size of discrete Fourier transform.

6 . An apparatus for transmitting a common signal in hybrid beamforming, comprising:
an analog common signal acquiring module, configured to acquire an analog common signal to be transmitted; an analog beamformer obtaining module, configured to select a different codeword for each RF chain from a codebook for analog beamforming and obtain an analog beamformer; an analog beamforming module, configured to beamform the analog common signal to be transmitted in each RF chain according to the analog beamformer; and a signal transmitting module, configured to transmit the beamformed analog common signal in each RF chain.

7 . The apparatus of claim 6 , further comprising:
a codeword group dividing module, configured to divide codewords in the codebook for analog beamforming into at least two codeword groups, wherein each codeword group includes at least one codeword; wherein the analog beamformer obtaining module is configured to select different codeword groups for adjacent timeslots, select a different codeword from the selected codeword group for each RF chain and obtain an analog beamformer.

8 . The apparatus of claim 7 , wherein the codeword group dividing module is configured to divide codewords in the codebook for analog beamforming into at least two codeword groups according to users' distribution.

9 . The apparatus of claim 6 , further comprising:
a digital common signal acquiring module, configured to acquire a digital common signal for generating the analog common signal to be transmitted; a digital beamformer obtaining module, configured to acquire a cyclic shift for each RF chain according to a principle of using different cyclic shifts for RF chains corresponding to adjacent beams, and obtain a digital beamformer using the acquired cyclic shift; a digital beamforming module, configured to beamform the digital common signal in each RF chain using the digital beamformer in digital baseband.

10 . The apparatus of claim 9 , further comprising:
a cyclic shift calculating module, configured to calculate the cyclic shift according to a maximum multipath delay spread of a channel impulse response and a size of discrete Fourier transform, and send the cyclic shift to the digital beamformer generating module.

11 . A device for transmitting a common signal in hybrid beamforming, the device comprises a processor and a memory communicated with the processor; in the memory, the instructions that are executed by the processor are stored, comprising an analog common signal acquiring instruction, an analog beamformer obtaining instruction, an analog beamforming instruction, and a signal transmitting instruction, wherein the analog common signal acquiring instruction indicates to acquire an analog common signal to be transmitted;
the analog beamformer obtaining instruction indicates to select a different codeword for each RF chain from a codebook for analog beamforming and obtain an analog beamformer; the analog beamforming instruction indicates to beamform the analog common signal to be transmitted in each RF chain according to the analog beamformer; and the signal transmitting instruction indicates to transmit the beamformed analog common signal in each RF chain.

12 . The device of claim 11 , wherein the instructions further comprise a codeword group dividing instruction, wherein
the codeword group dividing instruction indicates to divide codewords in the codebook for analog beamforming into at least two codeword groups, wherein each codeword group includes at least one codeword; the analog beamformer obtaining instruction indicates to select different codeword groups for adjacent timeslots, select a different codeword from the selected codeword group for each RF chain and obtain an analog beamformer.

13 . The device of claim 11 , wherein the instructions further comprise a digital common signal acquiring instruction, a digital beamformer obtaining instruction and a digital beamforming instruction, wherein
the digital common signal acquiring instruction indicates to acquire a digital common signal for generating the analog common signal to be transmitted; the digital beamformer obtaining instruction indicates to acquire a cyclic shift for each RF chain according to a principle of using different cyclic shifts for RF chains corresponding to adjacent beams, and obtain a digital beamformer using the acquired cyclic shift; the digital beamforming instruction indicates to beamform the digital common signal in each RF chain using the digital beamformer in digital baseband.

Assignees

• Ntt Docomo Inc

Inventors

• Xi Wei
• Hou Xiaolin
• Jiang Huiling

Classifications

• H04B7/0686 Primary

  Hybrid systems, i.e. switching and simultaneous transmission · CPC title

• H04B7/0671

  using different delays between antennas · CPC title

• H04B7/0617

  for beam forming · CPC title

• H04B7/0456 Primary

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