Frequency domain multiplex optical transmission

    公开(公告)号:US09859984B2

    公开(公告)日:2018-01-02

    申请号:US15281986

    申请日:2016-09-30

    摘要: A transmitter comprises a complex mixer to generate a single I analog drive signal and a single Q analog drive signal, and a single multi-dimensional optical modulator configured to modulate an optical carrier light using the single I analog drive signal and the single Q analog drive signal to produce a modulated optical signal for transmission. Alternatively, a transmitter comprises a complex mixer to generate two I analog drive signals and two Q analog drive signals, and a single multi-dimensional multiple-electrode optical modulator configured to modulate an optical carrier light using the analog drive signals to produce a modulated optical signal for transmission. In both transmitters, the optical carrier light is produced by a single laser, and frequency components of the first data signal are located in a different portion of a spectrum of the modulated optical signal than frequency components of the second data signal.

    Staggered parity
    3.
    发明授权

    公开(公告)号:US09831987B2

    公开(公告)日:2017-11-28

    申请号:US15378834

    申请日:2016-12-14

    摘要: Forward Error Correction technique: parity vectors are computed such that each parity vector spans multiple FEC frames; in a given FEC frame, a first set of syndrome bits are due to the parity vectors, and a second set of syndrome bits satisfy FEC equations that involve bits of the given FEC frame including the first set of syndrome bits; and the parity vectors are staggered with respect to any sequence in which the FEC frames are processed. Values of decoded bits of a first frame are deduced from known bits of a first parity vector having an effective length of one frame. For parity vectors having an effective length greater than one frame, a Log Likelihood Ratio of each unknown bit associated with the first frame is updated based on known and unknown bits of each parity vector. First frame is decoded using deduced bit values and updated LLR values.

    Staggered parity
    4.
    发明授权
    Staggered parity 有权
    交错平价

    公开(公告)号:US09537608B2

    公开(公告)日:2017-01-03

    申请号:US14564195

    申请日:2014-12-09

    摘要: In a Forward Error Correction (FEC) technique, parity vectors are computed such that: each parity vector spans a set of frames; a subset of bits of each frame is associated with parity bits in each parity vector; and a location of parity bits associated with one frame in one parity vector is different from that of parity bits associated with the frame in another parity vector. Values of decoded bits of a first frame are deduced from known parity bits of a first parity vector having an effective length of one frame. For parity vectors having, an effective length greater than one frame, a Log Likelihood Ratio of each unknown parity bit associated with the first frame is updated based on known and unknown parity bits of each parity vector. The first frame is decoded using the deduced bit values and the updated LLR values.

    摘要翻译: 在前向纠错(FEC)技术中,计算奇偶校验向量,使得:每个奇偶校验向量跨越一组帧; 每个帧的比特的子集与每个奇偶校验向量中的奇偶校验位相关联; 并且与一个奇偶校验向量中的一帧相关联的奇偶校验位的位置与在另一个奇偶校验向量中与该帧相关联的奇偶校验位的位置不同。 从具有一帧的有效长度的第一奇偶校验向量的已知奇偶校验位推导第一帧的解码比特的值。 对于具有大于一帧的有效长度的奇偶校验向量,基于每个奇偶校验向量的已知和未知奇偶校验位来更新与第一帧相关联的每个未知奇偶校验位的对数似然比。 使用推导的比特值和更新的LLR值对第一帧进行解码。

    Constrained continuous phase modulation and demodulation in an optical communications system
    5.
    发明授权
    Constrained continuous phase modulation and demodulation in an optical communications system 有权
    光通信系统中的约束连续相位调制和解调

    公开(公告)号:US08983309B2

    公开(公告)日:2015-03-17

    申请号:US13371846

    申请日:2012-02-13

    IPC分类号: H04B10/06 H04B10/04

    CPC分类号: H04B10/5561

    摘要: A transmitter in an optical communications system includes a digital signal processor for processing a data signal to generate a sample stream encoding successive symbols in accordance with a constrained phase modulation scheme having a constellation of at least two symbols and a modulation phase constrained to a phase range spanning less than 4π. A digital-to-analog converter converts the sample stream into a corresponding analog drive signal. A finite range phase modulator modulates a phase of a continuous wavelength channel light in accordance with the analog drive signal, to generate a modulated channel light for transmission through the optical communications system. A receiver in the optical communications system includes an optical stage for detecting phase and amplitude of the modulated channel light and for generating a corresponding sample stream, and a digital signal processor for processing the sample stream to estimate each successive symbol of the modulated channel light.

    摘要翻译: 光通信系统中的发射机包括数字信号处理器,用于处理数据信号以产生根据具有至少两个符号的星座的约束相位调制方案编码连续码元的采样流,以及限制为相位范围的调制相位 跨度小于4&pgr。 数模转换器将采样流转换成相应的模拟驱动信号。 有限范围相位调制器根据模拟驱动信号调制连续波长信道光的相位,以产生用于通过光通信系统传输的调制信道光。 光通信系统中的接收机包括用于检测调制信道光的相位和幅度并用于产生相应样本流的光学级,以及用于处理样本流以估计调制信道光的每个连续符号的数字信号处理器。

    Forward error correction with compression coding

    公开(公告)号:US11201695B2

    公开(公告)日:2021-12-14

    申请号:US17226287

    申请日:2021-04-09

    摘要: A method performed at an electronic device comprises receiving information bits, a first nub, and a second nub, each nub comprising redundant values; calculating first calculated determiners from first subsets of the information bits along a first dimension; calculating first corrected determiners by applying first FEC decoding to a combination of the first calculated determiners and the first nub; correcting at least one error in the information bits using a difference between the first corrected determiners and the first calculated determiners; calculating second calculated determiners from second subsets of the information bits along a second dimension that differs from the first dimension; calculating second corrected determiners by applying second FEC decoding to a combination of the second calculated determiners and the second nub; and correcting at least one additional error in the information bits using a difference between the second corrected determiners and the second calculated determiners.

    Clock phase detection using interior spectral components

    公开(公告)号:US11126219B2

    公开(公告)日:2021-09-21

    申请号:US16599678

    申请日:2019-10-11

    摘要: A receiver apparatus comprises circuitry configured for storing a first sequence of values. At the receiver apparatus, a communications signal is received which conveys a second sequence of values, the second sequence of values being related to the first sequence of values. According to some examples, the second sequence of values is identical to the first sequence of values. At the receiver apparatus, P results are calculated from a cross-correlation of the first sequence of values with at least a portion of a representation of the communications signal, where P is a positive integer. According to some examples, P≥2. An estimate of a phase offset of a continuous clock is calculated as a function of the P results. According to some examples, the function is a non-linear function. The estimate of the clock phase offset may be used to achieve clock recovery at the receiver apparatus.

    Nonlinear digital signal processing for additive noise removal

    公开(公告)号:US11038599B1

    公开(公告)日:2021-06-15

    申请号:US17064910

    申请日:2020-10-07

    摘要: A receiver applies first processing to a digital representation of a received signal to generate a first processed signal having first additive noise and first linear inter-symbol interference (ISI), the first processing comprising a substantially linear operation designed to substantially minimize a sum of variances of the first additive noise and the first linear ISI. The receiver applies second processing to the first processed signal to generate a second processed signal having second additive noise and second linear ISI, the second processing comprising a substantially nonlinear operation designed (i) to make a variance of the second additive noise substantially lower than the variance of the first additive noise, and (ii) to make a sum of the variance of the second additive noise and a variance of the second linear ISI substantially lower than the sum of the variances of the first additive noise and first linear ISI.

    Optical modulation schemes having reduced nonlinear optical transmission impairments
    9.
    发明授权
    Optical modulation schemes having reduced nonlinear optical transmission impairments 有权
    具有降低的非线性光传输损伤的光调制方案

    公开(公告)号:US09143238B2

    公开(公告)日:2015-09-22

    申请号:US13969694

    申请日:2013-08-19

    CPC分类号: H04B10/532 H04B10/516

    摘要: A method of transmitting a data signal using an optical transmitter of an optical communications system. The optical transmitter is configured to modulate an optical carrier in successive signalling intervals to generate an optical signal. A modulation scheme is provided which comprises a multi-dimensional symbol constellation. The modulation scheme is designed such that an average degree of polarization of a modulated optical signal output from the optical transmitter has a first value when averaged across a first signaling interval, and has a second value when averaged across more than one and fewer than 100 signaling intervals. The second value is less than 10 percent of the first value. During run-time, an encoder of the optical transmitter encoding a data signal to be transmitted as symbols of the constellation, and a modulator of the optical transmitter modulating available dimensions of the optical carrier in accordance with the symbols.

    摘要翻译: 一种使用光通信系统的光发射机发送数据信号的方法。 光发射机被配置为在连续的信令间隔中调制光载波以产生光信号。 提供了一种包括多维符号星座的调制方案。 调制方案被设计成使得当从第一信令间隔平均时,从光发送器输出的调制光信号的平均偏振度具有第一值,并且当平均多于一个且少于100个信令时具有第二值 间隔 第二个值小于第一个值的10%。 在运行时间期间,光发送器的编码器编码要作为星座符号发送的数据信号,以及根据符号调制光载波的可用尺寸的光发射机的调制器。

    Chain encoding and decoding of high speed signals
    10.
    发明授权
    Chain encoding and decoding of high speed signals 有权
    链式编码和解码高速信号

    公开(公告)号:US09088387B2

    公开(公告)日:2015-07-21

    申请号:US13949627

    申请日:2013-07-24

    摘要: A method of recovering a value of a symbol received through an optical communications system. A multi-bit estimate of the symbol is subdivided into a first part and a second part, each part including at least one respective bit of the estimate. A most likely value of the first part is detected. The most likely value of the first part is processed using a Forward Error Correction (FEC) decoder to generate a corrected first part value, which is used to detect a most likely value of the second part. The most likely value of the second part is then processed by the FEC decoder to generate a corrected second part, which is combined with the corrected first part to recover the value of the symbol.

    摘要翻译: 一种恢复通过光通信系统接收的符号的值的方法。 符号的多位估计被细分为第一部分和第二部分,每个部分包括估计的至少一个相应位。 检测到第一部分的最有可能的值。 使用前向纠错(FEC)解码器处理第一部分的最可能的值,以产生校正的第一部分值,其用于检测第二部分的最可能的值。 然后由FEC解码器处理第二部分的最可能的值,以产生校正的第二部分,其与校正的第一部分组合以恢复符号的值。