公开(公告)号：US20190222337A1

公开(公告)日：2019-07-18

申请号：US16363467

申请日：2019-03-25

Applicant: PhasorLab, Inc.

Inventor： Jian Cui ,  Joshua C. Park ,  Paul McFarthing

IPC: H04J11/00 ,  H04L27/26 ,  H04L25/03 ,  H04L27/36

CPC classification number: H04J11/0036 ,  H04J2011/0096 ,  H04J2211/006 ,  H04L25/03159 ,  H04L25/03821 ,  H04L27/2626 ,  H04L27/2636 ,  H04L27/265 ,  H04L27/2657 ,  H04L27/2676 ,  H04L27/36

Abstract: Systems and methods for canceling carrier frequency offset (CFO) and sampling frequency offset (SFO) in a radio receive chain are disclosed. In one embodiment, a method is disclosed, comprising: receiving a sub-frame via a radio receive chain in a time domain; performing per-user filtering on the sub-frame to obtain a signal for a particular user; obtaining a CFO correction signal; adding the CFO correction signal in the time domain to perform a CFO correction step on the signal for the particular user; performing an FFT on the output of the CFO correction step to obtain samples in a frequency domain; adding an SFO correction signal in the frequency domain to perform an SFO correction to the output of FFT step; and demodulating the output of SFO correction step, thereby performing CFO and SFO correction while reducing inter-carrier interference (ICI).

公开(公告)号：US20180234933A1

公开(公告)日：2018-08-16

申请号：US15949761

申请日：2018-04-10

Applicant: PhasorLab, Inc.

Inventor： Joshua C. Park

IPC: H04W56/00 ,  H04L7/00 ,  H04L27/36 ,  G01S3/18 ,  H04W64/00 ,  H04L27/00 ,  H04B7/0413 ,  H04L25/02

CPC classification number: H04W56/006 ,  G01S3/18 ,  H04B7/0413 ,  H04L7/0016 ,  H04L25/02 ,  H04L27/0014 ,  H04L27/364 ,  H04L2027/003 ,  H04L2027/0046 ,  H04L2027/0053 ,  H04L2027/0067 ,  H04W56/0035 ,  H04W64/006

Abstract: A method is disclosed for synchronization, comprising obtaining baseband signal samples of a baseband information signal having an in-phase signal sample and a quadrature signal sample, the baseband information signal having been generated by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency, the modulated carrier signal being an in-phase signal and quadrature signal having a substantially uncorrelated nature and derived from different input data sets; determining an offset frequency rotation based on an estimated residual correlation between the in-phase signal samples and the quadrature signal samples; and, deriving synchronization information from the offset frequency rotation, wherein the received modulated carrier signal is a quadrature-modulated signal with arbitrary orthogonal in-phase and quadrature signal components.

公开(公告)号：US09942869B2

公开(公告)日：2018-04-10

申请号：US14727861

申请日：2015-06-01

Applicant: PhasorLab, Inc.

Inventor： Joshua C. Park

IPC: H04W56/00 ,  H04L7/00 ,  H04L27/00 ,  H04B7/0413 ,  H04L25/02 ,  H04L27/36 ,  G01S3/18 ,  H04W64/00

CPC classification number: H04W56/006 ,  G01S3/18 ,  H04B7/0413 ,  H04L7/0016 ,  H04L25/02 ,  H04L27/0014 ,  H04L27/364 ,  H04L2027/003 ,  H04L2027/0046 ,  H04L2027/0053 ,  H04L2027/0067 ,  H04W56/0035 ,  H04W64/006

Abstract: A method comprising generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency; obtaining baseband signal samples of the baseband information signal having a baseband signal magnitude and a baseband signal phase; determining a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold; and, applying a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase.

公开(公告)号：US20170118060A1

公开(公告)日：2017-04-27

申请号：US15397689

申请日：2017-01-03

Applicant: PhasorLab, Inc.

Inventor： Jian Cui ,  Joshua C. Park

IPC: H04L27/26 ,  H04J11/00

CPC classification number: H04L27/2659 ,  H04J11/0036 ,  H04L5/0007 ,  H04L27/265 ,  H04L27/2657 ,  H04L27/2676 ,  H04L2025/0342

Abstract: A synchronizing radio receiver is disclosed, comprising: an analog baseband receive chain and a digital baseband receive chain. The digital baseband receive chain may comprise an analog to digital converter, a frame synchronization module, a frequency synchronization module, and an orthogonal frequency division multiplexing (OFDM) demodulator, wherein the frequency synchronization module is configured to cross-correlate a plurality of in-phase and quadrature samples to generate a synchronization signal and output the synchronization signal to a local oscillator in the analog baseband receive chain. The digital baseband receive chain may also further comprise a carrier frequency offset (CFO)/sampling frequency offset (SFO) correction module coupled to a frequency synchronization module configured to cross-correlate a plurality of in-phase and quadrature samples, with the CFO/SFO correction module configured to apply correction in a digital domain before outputting a corrected signal to the OFDM demodulator.

公开(公告)号：US09635634B2

公开(公告)日：2017-04-25

申请号：US14727859

申请日：2015-06-01

Applicant: PhasorLab, Inc.

Inventor： Joshua C. Park

IPC: H04L7/00 ,  H04W56/00 ,  H04L27/00 ,  H04B7/0413 ,  H04L25/02 ,  H04L27/36 ,  G01S3/18 ,  H04W64/00

CPC classification number: H04W56/006 ,  G01S3/18 ,  H04B7/0413 ,  H04L7/0016 ,  H04L25/02 ,  H04L27/0014 ,  H04L27/364 ,  H04L2027/003 ,  H04L2027/0046 ,  H04L2027/0053 ,  H04L2027/0067 ,  H04W56/0035 ,  H04W64/006

Abstract: A method comprising generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency; obtaining baseband signal samples of the baseband information signal having a baseband signal magnitude and a baseband signal phase; determining a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold; and, applying a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase.

公开(公告)号：US09585115B2

公开(公告)日：2017-02-28

申请号：US15090338

申请日：2016-04-04

Applicant: PhasorLab, Inc.

Inventor： Joshua C. Park

IPC: H04L7/00 ,  H04W56/00 ,  H04L27/00 ,  H04B7/04 ,  H04L25/02 ,  H04L27/36 ,  G01S3/18 ,  H04W64/00

CPC classification number: H04W56/006 ,  G01S3/18 ,  H04B7/0413 ,  H04L7/0016 ,  H04L25/02 ,  H04L27/0014 ,  H04L27/364 ,  H04L2027/003 ,  H04L2027/0046 ,  H04L2027/0053 ,  H04L2027/0067 ,  H04W56/0035 ,  H04W64/006

Abstract: Systems and methods are disclosed for synchronization and positioning, one of which comprises determining a first phase offset for a known signal received at a first antenna by plotting a first arbitrary set of phase corrections and finding a phase offset corresponding to a greatest reflectional symmetry within the first arbitrary set of phase corrections, determining a second phase offset for a known signal received at a second antenna by plotting a second arbitrary set of phase corrections and finding a phase offset corresponding to a greatest reflectional symmetry within the second arbitrary set of phase corrections, calculating an angle of arrival for the known signal from the transmitter based on the first and the second phase offset for the known signal as received at the first antenna and the second antenna, and calculating a positioning vector for a direction of the transmitter.

Abstract translation: 公开了用于同步和定位的系​​统和方法，其中之一包括通过绘制第一任意一组相位校正来确定在第一天线处接收到的已知信号的第一相位偏移，并且找出对应于最大反射对称的相位偏移 第一任意的相位校正集合，通过绘制第二任意的相位校正集合并且找出对应于第二任意组相位校正中的最大反射对称性的相位偏移来确定在第二天线处接收到的已知信号的第二相位偏移， 根据在第一天线和第二天线处接收到的已知信号的第一和第二相位偏移，计算来自发射机的已知信号的到达角度，以及计算发射机方向的定位矢量。