公开(公告)号：US20180131423A1

公开(公告)日：2018-05-10

申请号：US15347027

申请日：2016-11-09

Applicant: Facebook, Inc.

Inventor： Sungwoo Park ,  Ali YAZDAN PANAH

IPC: H04B7/06 ,  H04B7/04

CPC classification number: H04B7/0617 ,  H04B7/0452 ,  H04B7/0456 ,  H04L25/03343 ,  H04W88/08

Abstract: Apparatuses, methods, and systems for beamforming in antenna systems are disclosed. A method includes determining an unconstrained analog precoding matrix (FRF,UC), wherein the unconstrained analog precoding matrix (FRF,UC) is determined based on M dominant eigenvectors of the sum of spatial channel covariance matrices of K users, and wherein K indicates a number of users communicating with a base station. The method further includes determining a constrained analog precoding matrix (FRF) based on the unconstrained analog precoding matrix (FRF,UC), determining a compensation matrix (FCM), digitally multiplying K inputs with a multiple-input multiple-output (MIMO) precoding matrix (FMU) generating M outputs, digitally multiplying the M outputs with the compensation matrix (FCM) generating M compensation outputs, generating M analog frequency-up-converted signals based on the M compensation outputs, and analog multiplying the M analog frequency-up-converted signals with the analog precoding matrix (FRF) generating N output signals for transmission, wherein N is greater than M.

公开(公告)号：US09967014B1

公开(公告)日：2018-05-08

申请号：US15347027

申请日：2016-11-09

Applicant: Facebook, Inc.

Inventor： Sungwoo Park ,  Ali Yazdan Panah

IPC: H04B7/06 ,  H04B7/04 ,  H04B7/0456 ,  H04W88/08 ,  H04L25/03 ,  H04B7/0452

CPC classification number: H04B7/0617 ,  H04B7/0452 ,  H04B7/0456 ,  H04L25/03343 ,  H04W88/08

Abstract: Apparatuses, methods, and systems for beamforming in antenna systems are disclosed. A method includes determining an unconstrained analog precoding matrix (FRF,UC), wherein the unconstrained analog precoding matrix (FRF,UC) is determined based on M dominant eigenvectors of the sum of spatial channel covariance matrices of K users, and wherein K indicates a number of users communicating with a base station. The method further includes determining a constrained analog precoding matrix (FRF) based on the unconstrained analog precoding matrix (FRF,UC), determining a compensation matrix (FCM), digitally multiplying K inputs with a multiple-input multiple-output (MIMO) precoding matrix (FMU) generating M outputs, digitally multiplying the M outputs with the compensation matrix (FCM) generating M compensation outputs, generating M analog frequency-up-converted signals based on the M compensation outputs, and analog multiplying the M analog frequency-up-converted signals with the analog precoding matrix (FRF) generating N output signals for transmission, wherein N is greater than M.

公开(公告)号：US10237828B2

公开(公告)日：2019-03-19

申请号：US15294691

申请日：2016-10-15

Applicant: Facebook, Inc.

Inventor： Jeonghun Park ,  Sungwoo Park ,  Ali Yazdan Panah

IPC: H04W72/00 ,  H04W52/02

Abstract: Apparatuses, methods, and systems for selecting an ADC for each RF chain of an RRU are disclosed. One embodiment of the RRU includes a plurality of antennas and a plurality of RF chains configured to receive a plurality of wireless signals, A plurality of outputs of the RRU connected to a front-haul, wherein the front-haul electrically connects the plurality of outputs of the RRU to a baseband unit (BBU), wherein each of the outputs is connected to an output of one of a plurality of ADCs. Further, the RRU selects a one of the plurality of ADCs having the plurality of ADC resolutions for each of the RF chains based on the capacity of the front-haul, a channel gain of each of the RF chains, and a performance parameter of the RRU. A switch connects each of the RF chains to a corresponding one of the plurality of ADCs.

公开(公告)号：US20180110007A1

公开(公告)日：2018-04-19

申请号：US15294691

申请日：2016-10-15

Applicant: Facebook, Inc.

Inventor： Jeonghun Park ,  Sungwoo Park ,  Ali YAZDAN PANAH

IPC: H04W52/02

CPC classification number: H04W52/0258 ,  H04W52/0206 ,  H04W52/0232 ,  Y02D70/00

Abstract: Apparatuses, methods, and systems for selecting an ADC for each RF chain of an RRU are disclosed. One embodiment of the RRU includes a plurality of antennas and a plurality of RF chains configured to receive a plurality of wireless signals, A plurality of outputs of the RRU connected to a front-haul, wherein the front-haul electrically connects the plurality of outputs of the RRU to a baseband unit (BBU), wherein each of the outputs is connected to an output of one of a plurality of ADCs. Further, the RRU selects a one of the plurality of ADCs having the plurality of ADC resolutions for each of the RF chains based on the capacity of the front-haul, a channel gain of each of the RF chains, and a performance parameter of the RRU. A switch connects each of the RF chains to a corresponding one of the plurality of ADCs.