公开(公告)号：US09692521B1

公开(公告)日：2017-06-27

申请号：US14793433

申请日：2015-07-07

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Ryohei Urata ,  Christopher Lyle Johnson

IPC: H04J14/06 ,  H04B10/58 ,  H04B10/2507 ,  H04B10/556

CPC classification number: H04B10/58 ,  H04B10/2507 ,  H04B10/2572 ,  H04B10/532 ,  H04B10/556 ,  H04J14/06

Abstract: This disclosure provides systems, methods, and apparatus for mitigating the effects of an optical link in a communication system on polarization angles of signals transmitted over the optical link. The communication system can include an optical transmitter transmitting polarization-division multiplexed (PDM) optical signals over the optical link and a direct-detection receiver for receiving the PDM optical signals. The transmitter can include a polarization compensation unit for receiving estimated values of link polarization parameters from the receiver. The receiver uses the estimated values to pre-distort modulator drive and bias signals and to adjust the relative phase between modulated optical signals. The transmitter can also transmit training optical signals to the receiver over the optical link. The receiver uses the training optical signals to estimate the values of link polarization parameters. The receiver also can include a crosstalk mitigation unit for mitigating effects of crosstalk between the PDM optical signals.

公开(公告)号：US20170201330A1

公开(公告)日：2017-07-13

申请号：US14991826

申请日：2016-01-08

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Ryohei Urata ,  Erji Mao ,  Hong Liu ,  Christopher Lyle Johnson

IPC: H04B10/69

CPC classification number: H04B10/6971 ,  H04B10/697

Abstract: This disclosure provides systems, methods, and apparatus for mitigating the effects of interference signals on optical signals received at a direct-detection optical receivers. The optical receivers are capable of attenuating interference noise signals resulting from the interference between a transmitted optical signal transmitted from a transmitter to the optical receiver and one or more additional signals received at the optical receiver. The interference can be due to multi-path interference or due to in-band interference. The receivers include a tunable filter for filtering the received optical signal to remove the interference. A frequency offset module processes the received optical signal to determine a frequency offset indicative of the difference between the carrier frequencies of a modulated optical signal and an interference optical signal. The offset frequency and a bandwidth determined by the frequency offset module can be used to adjust the tunable filter to remove the interference signal from the received signal.

公开(公告)号：US09331780B1

公开(公告)日：2016-05-03

申请号：US14274758

申请日：2014-05-11

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Hong Liu

IPC: H04B10/12 ,  H04B10/25 ,  H04B10/27

CPC classification number: H04B10/25 ,  H04B10/0775 ,  H04B10/27

Abstract: This disclosure provides systems, methods, and apparatus for an energy efficient communication system. The communication system can include a transmitter, a receiver and a communication link for communicating data between the transmitter and the receiver. In some implementations, the receiver determines a signal quality parameter (SQP) value of the received data, and communicates the SQP value to the transmitter. In some implementations, the transmitter adjusts one or more operational parameters of the transmitter to reduce power based on the received SQP value being less than a threshold value. In some implementations, the receiver also adjusts one or more operational parameters of the receiver based on the SQP value being less than a threshold value. In some implementations, the receiver can communicate the SQP value to the transmitter over out-of-band communication links.

Abstract translation: 本公开提供了一种用于节能通信系统的系统，方法和装置。 通信系统可以包括用于在发射机和接收机之间传送数据的发射机，接收机和通信链路。 在一些实现中，接收机确定接收数据的信号质量参数（SQP）值，并将SQP值传送给发射机。 在一些实施方案中，发射机调整发射机的一个或多个操作参数，以便基于所接收的SQP值小于阈值来降低功率。 在一些实现中，接收机还基于SQP值小于阈值来调整接收机的一个或多个操作参数。 在一些实现中，接收机可以通过带外通信链路将SQP值传送到发射机。

公开(公告)号：US09325423B1

公开(公告)日：2016-04-26

申请号：US14447156

申请日：2014-07-30

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Ryohei Urata

IPC: H04B10/532 ,  H04B10/61 ,  H04J14/06

CPC classification number: H04B10/6162 ,  H04B10/532 ,  H04J14/06

Abstract: This disclosure provides systems, methods, and apparatus for improving a signal-to-noise ratio of a signal transmitted over a communication link. The communication system can include a transmitter, a receiver and a communication link for communicating data between the transmitter and the receiver. In some implementations, the transmitter employs a modulator for generating a modulated data signal and a complementary modulated data signal and send over the fiber link through two orthogonal polarizations. The receiver utilizes both the modulated data signal and the complementary modulated data signal for regenerating the transmitted data at the receiver. In some implementations, the receiver determines and transmits a polarization parameter to the transmitter, which adjusts the polarizations of the transmitted modulated and complementary modulated data signals to compensate for polarization angle rotation introduced by the communication link.

Abstract translation: 本公开提供了用于改善通过通信链路发送的信号的信噪比的系统，方法和装置。 通信系统可以包括用于在发射机和接收机之间传送数据的发射机，接收机和通信链路。 在一些实施方式中，发射机采用调制器来产生调制数据信号和互补调制数据信号，并通过两个正交偏振发送光纤链路。 接收机利用调制数据信号和互补调制数据信号来在接收机处再生发送的数据。 在一些实施方式中，接收机确定并向发射机发送偏振参数，该偏振参数调整发送的调制和互补调制数据信号的极化，以补偿由通信链路引入的偏振角旋转。

公开(公告)号：US09998235B2

公开(公告)日：2018-06-12

申请号：US14991826

申请日：2016-01-08

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Ryohei Urata ,  Erji Mao ,  Hong Liu ,  Christopher Lyle Johnson

IPC: H04B10/00 ,  H04B10/69

CPC classification number: H04B10/6971 ,  H04B10/697

Abstract: This disclosure provides systems, methods, and apparatus for mitigating the effects of interference signals on optical signals received at a direct-detection optical receivers. The optical receivers are capable of attenuating interference noise signals resulting from the interference between a transmitted optical signal transmitted from a transmitter to the optical receiver and one or more additional signals received at the optical receiver. The interference can be due to multi-path interference or due to in-band interference. The receivers include a tunable filter for filtering the received optical signal to remove the interference. A frequency offset module processes the received optical signal to determine a frequency offset indicative of the difference between the carrier frequencies of a modulated optical signal and an interference optical signal. The offset frequency and a bandwidth determined by the frequency offset module can be used to adjust the tunable filter to remove the interference signal from the received signal.

公开(公告)号：US09231704B1

公开(公告)日：2016-01-05

申请号：US14275166

申请日：2014-05-12

Applicant: Google Inc.

Inventor： Xiang Zhou ,  Erji Mao

IPC: H04B10/54 ,  H04B10/50 ,  H04B10/524

CPC classification number: H04B10/504 ,  H04B10/58

Abstract: In some implementations, the output of a directly modulated laser (DML) includes nonlinearities with respect to the input signal driving the DML. When the DML is transmitting an amplitude modulated signal, the nonlinearities can induce noise into the signal, which makes it difficult for a receiving node to correctly decode the received signal. The system and methods described herein pre-correct the error caused by the nonlinearities of the DML by filtering (or pre-correcting) the data signal that drives the DML.

Abstract translation: 在一些实现中，直接调制激光器（DML）的输出包括相对于驱动DML的输入信号的非线性。 当DML发送幅度调制信号时，非线性可以将噪声引入到信号中，这使得接收节点难以对接收到的信号进行正确的解码。 本文描述的系统和方法通过过滤（或预校正）驱动DML的数据信号来校正由DML的非线性引起的误差。