公开(公告)号：US20200106648A1

公开(公告)日：2020-04-02

申请号：US16146079

申请日：2018-09-28

申请人： AHMED MOHAMED IBRAHIM MEDRA ,  HOSSEIN NAJAFI ,  ZHUHONG ZHANG

发明人： AHMED MOHAMED IBRAHIM MEDRA ,  HOSSEIN NAJAFI ,  ZHUHONG ZHANG

IPC分类号： H04L25/03 ,  H04B1/10

摘要： Apparatus and methods are provided for noise-whitening post-compensation in a receiver. A first apparatus includes a first whitening filter configured to filter a received signal comprising symbols to generate a first filtered signal. The first apparatus further includes a first decision feedback equalizer having an input coupled to an output of the first whitening filter to receive the first filtered signal. The first decision feedback equalizer is configured to apply decision feedback equalization to the first filtered signal to generate estimates for the symbols of the received signal. A second apparatus includes a decision device configured to generate a symbols decision based on a received signal comprising symbols, a noise predictor configured to predict noise in the received signal, and a subtractor configured to subtract the predicted noise from the received signal to generate a symbols estimate.

公开(公告)号：US20190296832A1

公开(公告)日：2019-09-26

申请号：US16354897

申请日：2019-03-15

申请人： NASH'AT ABUGHALIEH ,  ZHUHONG ZHANG

发明人： NASH'AT ABUGHALIEH ,  ZHUHONG ZHANG

IPC分类号： H04B10/61 ,  H04L27/01

摘要： Systems and methods are provided for adaptive equalization, for example for use with coherent optical reception. The equalizer has a loop for updating taps of an adaptive linear filter forming part of the equalizer. In the loop, an error calculator calculates an error, a gradient calculator calculates a gradient of the error or filtered error. One or more gradient filters are used to filter the gradient, and the filtered gradient is used to update the taps of the adaptive linear filter. A reduction in self oscillation in the equalizer is achieved by separating the frequencies with channel features that change with time and scaling them up to speed up convergence of the equalizer.

公开(公告)号：US20210119850A1

公开(公告)日：2021-04-22

申请号：US17037840

申请日：2020-09-30

申请人： WING CHAU NG ,  XUEFENG TANG ,  ZHUHONG ZHANG

发明人： WING CHAU NG ,  XUEFENG TANG ,  ZHUHONG ZHANG

IPC分类号： H04L27/36 ,  H04L27/227 ,  H04L27/04 ,  H04B10/50 ,  H04B10/077

摘要： Methods and apparatus for coherent transmitter calibration are provided that employ direct detection (DD) using one single photodetector (PD). The provided method and apparatus do not require hardware for coherent reception, or additional ADCs for quality control. An additional optical tone is added to a QAM optical signal that is outside the band of the QAM optical signal. The result of this is that after direct detection, there is a correlation between the real and imaginary parts, and the imaginary part can be recovered with a Hilbert transform. The estimated QAM optical signal obtained by direct detection is used to perform a transmitter factory calibration method to calibrate for one or more transmitter impairments and/or to perform in-line self-calibration.

公开(公告)号：US20180138980A1

公开(公告)日：2018-05-17

申请号：US15352040

申请日：2016-11-15

申请人： ZHIPING JIANG ,  CHUANDONG LI ,  ZHUHONG ZHANG ,  XUEFENG TANG

发明人： ZHIPING JIANG ,  CHUANDONG LI ,  ZHUHONG ZHANG ,  XUEFENG TANG

IPC分类号： H04B10/40 ,  H04Q11/00 ,  H04B3/32 ,  H04B10/556

CPC分类号： H04B10/40 ,  H04B3/32 ,  H04B10/5563 ,  H04B10/572 ,  H04B10/61 ,  H04B2210/254 ,  H04J14/0282 ,  H04Q11/0067 ,  H04Q2011/0047

摘要： An optical transceiver is provided with an optical front end for receiving signal light comprising an optical sub-channel, and for providing an electrical signal based on the signal light; a light source optically coupled to the optical front end for providing local oscillator light thereto for mixing with the signal light; an electro-optical modulator coupled to the light source for receiving output light therefrom and for modulating the output light with digital information to obtain modulated light; and a signal processor operably coupled to the optical front end. The signal processor is configured for processing the electrical signal to obtain a frequency offset of the sub-channel; and adjusting an optical frequency of the modulated light based on the frequency offset. When applied to a multiple-access environment, this may allow access nodes to generate optical sub-channels in the uplink direction using the downlink optical signal as an optical frequency reference.

公开(公告)号：US20170063408A1

公开(公告)日：2017-03-02

申请号：US14840457

申请日：2015-08-31

申请人： MAHDI ZAMANI ,  AHIKAM AHARONY ,  ZHUHONG ZHANG ,  CHUANDONG LI ,  WEIKUN HOU

发明人： MAHDI ZAMANI ,  AHIKAM AHARONY ,  ZHUHONG ZHANG ,  CHUANDONG LI ,  WEIKUN HOU

IPC分类号： H04B1/10 ,  H04L27/26 ,  H04L27/00 ,  H04L5/00

CPC分类号： H04B1/40 ,  H04L27/0014 ,  H04L27/32

摘要： Provided is an apparatus and method for transmitting and receiving wireless signals. A transmitting apparatus has a signal processor and a transmitter. The signal processor is configured to generate a signal having a middle channel and at least one side channel. The transmitter is configured to wirelessly transmit the signal subject to a spectral mask that has shoulder regions. According to an embodiment of the invention, the signal processor generates the signal such that each side channel is positioned in one of the shoulder regions of the spectral mask. In this manner, bandwidth from the shoulder regions can be utilized by one or more side channels. Also provided is a receiving apparatus having a receiver configured to wirelessly receive the signal, and a signal processor configured to process the signal.

摘要翻译： 提供了一种用于发送和接收无线信号的装置和方法。 发送装置具有信号处理器和发送器。 信号处理器被配置为产生具有中间信道和至少一个侧信道的信号。 发射器被配置为无线地发射受到具有肩部区域的光谱掩模的信号。 根据本发明的实施例，信号处理器产生信号，使得每个侧面通道位于光谱掩模的一个肩部区域中。 以这种方式，来自肩部区域的带宽可被一个或多个侧面通道利用。 还提供了具有被配置为无线地接收信号的接收机的接收设备，以及被配置为处理该信号的信号处理器。

公开(公告)号：US20160380716A1

公开(公告)日：2016-12-29

申请号：US15258661

申请日：2016-09-07

申请人： ZHIPING JIANG ,  ZHUHONG ZHANG ,  XUEFENG TANG

发明人： ZHIPING JIANG ,  ZHUHONG ZHANG ,  XUEFENG TANG

IPC分类号： H04J14/02 ,  H04J14/06 ,  H04B10/516 ,  H04B10/25

CPC分类号： H04J14/0276 ,  H04B10/077 ,  H04B10/0775 ,  H04B10/2504 ,  H04B10/516 ,  H04B2210/075 ,  H04J14/06

摘要： The present applies to digital wavelength converters that convert, independently of the format in which optical data may be encoded, an input waveform at a first wavelength to an output waveform at a second wavelength. When operating in an environment where an input waveform has a pilot tone associated thereto, the method and system of the present disclosure allows for the removal of the pilot tone from the input waveform, and also allows for the addition of another pilot to the output waveform.