Training-aided feedforward channel equalization

    公开(公告)号:US10938483B1

    公开(公告)日:2021-03-02

    申请号:US16903792

    申请日:2020-06-17

    IPC分类号: H04B10/61 H04B10/69

    摘要: An optical signal modulated with a stream of symbols comprising a sequence of training symbols is received at a receiver. First equalizer circuitry calculates and applies first coefficients to digital signals representative of the optical signal, thereby resulting in first compensated signals. Second equalizer circuitry calculates second coefficients based on a correlation between the first compensated signals and digital signals representative of the sequence of training symbols and applies the second coefficients to the first compensated signals, thereby resulting in second compensated signals. Third equalizer circuitry calculates and applies third coefficients to the second compensated signals, thereby resulting in third compensated signals. The first, second, and third coefficients compensate for impairments in the optical signal varying at respective first, second, and third rates, where the third rate is higher than the first rate and lower than the second rate.

    Approximation of recursive least squares equalization

    公开(公告)号:US11239929B1

    公开(公告)日:2022-02-01

    申请号:US17203332

    申请日:2021-03-16

    IPC分类号: H04B3/46 H04B17/318

    摘要: A receiver is configured to detect, at a communication interface, a received signal that suffers from degradations incurred over a communication channel. The receiver applies an adaptive filter to a series of received blocks of a digital representation of the received signal, thereby generating respective filtered blocks, where each received block represents 2N frequency bins, and where N is a positive integer. The receiver calculates coefficients for use by the adaptive filter on a jth received block as a function of (i) error estimates associated with an (j−D−1)th filtered block, where D is a positive integer representing a number of blocks, and where j is a positive integer greater than (D−1); and (ii) an inverse of an approximate covariance matrix associated with the (j−D−1)th received block, where the approximate covariance matrix is a diagonal matrix of size L×L, and where L is a positive integer lower than 2N.

    Feedback equalization with delay compensation

    公开(公告)号:US11233568B1

    公开(公告)日:2022-01-25

    申请号:US17090135

    申请日:2020-11-05

    摘要: A receiver is configured to detect, at a communication interface, a received signal that suffers from degradations incurred over a communication channel. The receiver applies an adaptive filter to a series of received blocks of a digital representation of the received signal, thereby generating respective filtered blocks. The receiver calculates coefficients for use by the adaptive filter on an jth received block as a function of (i) error estimates associated with an (j−D−1)th filtered block, where D is a positive integer representing a number of blocks, and where j is a positive integer greater than (D−1); and (ii) delay compensation terms dependent on an estimate of a difference between coefficients used by the adaptive filter on an (j−D−1)th received block and coefficients used by the adaptive filter on an (j−1)th received block

    Sparse data compression
    7.
    发明授权
    Sparse data compression 失效
    稀疏数据压缩

    公开(公告)号:US08711015B2

    公开(公告)日:2014-04-29

    申请号:US13216295

    申请日:2011-08-24

    IPC分类号: H03M7/30

    CPC分类号: H03M7/30

    摘要: The invention relates to compressing of sparse data sets contains sequences of data values and position information therefor. The position information may be in the form of position indices defining active positions of the data values in a sparse vector of length N. The position information is encoded into the data values by adjusting one or more of the data values within a pre-defined tolerance range, so that a pre-defined mapping function of the data values and their positions is close to a target value. In one embodiment, the mapping function is defined using a sub-set of N filler values which elements are used to fill empty positions in the input sparse data vector. At the decoder, the correct data positions are identified by searching though possible sub-sets of filler values.

    摘要翻译: 本发明涉及压缩稀疏数据集包含数据值序列和位置信息。 位置信息可以是以长度N的稀疏向量定义数据值的活动位置的位置索引的形式。通过将一个或多个数据值调整在预定公差内,将位置信息编码为数据值 范围,使得数据值及其位置的预定义映射函数接近目标值。 在一个实施例中,使用N个填充值的子集定义映射函数,该子集用于填充输入稀疏数据向量中的空白位置。 在解码器处,通过搜索填充值可能的子集来识别正确的数据位置。

    Network apparatus enabling roaming across subnets
    8.
    发明授权
    Network apparatus enabling roaming across subnets 有权
    允许跨子网漫游的网络设备

    公开(公告)号:US08503396B2

    公开(公告)日:2013-08-06

    申请号:US13198084

    申请日:2011-08-04

    摘要: To enable a network apparatus to detect L3 roaming users and to take appropriate forwarding actions, L3 knowledge is introduced inside an L2 bridge forwarding table in the network apparatus. As a client moves from a subnet associated with a first network element to a subnet associated with the network apparatus, a determination is made regarding whether the client is roaming by evaluating a source IP address within a L3 packet header within a first frame received at the network apparatus. If, as a result of the evaluating step, it is determined that the client is roaming, the L2 bridge forwarding table is configured to include a source MAC address of the client together with information identifying a destination interface for use in directing client data traffic back towards the subnet associated with the first network element.

    摘要翻译: 为了使网络设备能够检测L3漫游用户并采取适当的转发动作,在网络设备的L2桥转发表中引入L3知识。 当客户端从与第一网元相关联的子网移动到与网络装置相关联的子网时,通过评估在第一帧中接收到的第一帧内的L3分组报头内的源IP地址来确定客户端是否正在漫游 网络设备 如果作为评估步骤的结果,确定客户端正在漫游,则L2桥转发表被配置为包括客户端的源MAC地址以及标识目的地接口的信息,以用于将客户端数据业务引导回来 朝向与第一网络元件相关联的子网。

    Method and system for a multi-microphone noise reduction
    9.
    发明授权
    Method and system for a multi-microphone noise reduction 有权
    多麦克风降噪的方法和系统

    公开(公告)号:US08660281B2

    公开(公告)日:2014-02-25

    申请号:US13147603

    申请日:2010-02-03

    IPC分类号: H04R25/00 H04R5/00

    摘要: A method for a multi microphone noise reduction in a complex noisy environment is proposed. A left and a right noise power spectral density for a left and a right noise input frame is estimated for computing a diffuse noise gain. A target speech power spectral density is extracted from the noise input frame. A directional noise gain is calculated from the target speech power spectral density and the noise power spectral density. The noisy input frame is filtered by Kalman filtering method. A Kalman based gain is generated from the Kalman filtered noisy frame and the noise power spectral density. A spectral enhancement gain is computed by combining the diffuse noise gain, the directional noise gain, and the Kalman based gain. The method reduces different combinations of diverse background noise and increases speech intelligibility, while guaranteeing to preserve the interaural cues of the target speech and directional background noises.

    摘要翻译: 提出了一种复杂嘈杂环境中多麦克风降噪的方法。 估计左和右噪声输入帧的左和右噪声功率谱密度用于计算漫反射噪声增益。 从噪声输入帧提取目标语音功率谱密度。 根据目标语音功率谱密度和噪声功率谱密度计算定向噪声增益。 噪声输入帧通过卡尔曼滤波法滤波。 从卡尔曼滤波噪声帧和噪声功率谱密度产生基于卡尔曼的增益。 通过组合漫射噪声增益,方向噪声增益和基于卡尔曼的增益来计算频谱增强增益。 该方法减少了不同背景噪声的不同组合,增加了语音清晰度,同时保证了目标语音和定向背景噪声的昼夜线索。

    Seamless roaming across wireless subnets using source address forwarding
    10.
    发明申请
    Seamless roaming across wireless subnets using source address forwarding 有权
    使用源地址转发无缝地漫游无线子网

    公开(公告)号:US20070153741A1

    公开(公告)日:2007-07-05

    申请号:US11646904

    申请日:2006-12-28

    IPC分类号: H04Q7/00

    摘要: To enable devices to detect L3 roaming users and to take appropriate forwarding actions, L3 knowledge is introduced inside a bridge in a non-intrusive way. In particular, as a client moves from a subnet associated with a first network element to a subnet associated with a second network element, a determination is made regarding whether the client is roaming. This is done by evaluating a source IP address within a L3 packet header within a first frame received at the second network element. If, as a result of the evaluating step, it is determined that the client is roaming, an L2 bridge forwarding table in the second network element is configured to include a source MAC address of the client together with information identifying at least a destination interface for use in directing client data traffic back towards the subnet associated with the first network element. The first frame is then forwarded. In one embodiment, the traffic is directed back towards the subnet associated with the first network element via a GRE encapsulation tunnel, although any convenient tunneling mechanism can be used. According to another feature, given information cached at the foreign access point is used to enable the roaming client to continue to seamlessly receive inbound traffic prior to or during the configuration of the L2 bridge forwarding table (i.e., before any outbound traffic is actually sent from the client).

    摘要翻译: 为了使设备能够检测L3漫游用户并采取适当的转发动作,L3桥梁内部以非侵入式方式引入知识。 特别地,当客户端从与第一网络元件相关联的子网移动到与第二网络元件相关联的子网时,确定客户端是否正在漫游。 这是通过评估在第二网络单元接收的第一帧内的L3分组报头内的源IP地址来完成的。 如果作为评估步骤的结果,确定客户端正在漫游,则第二网元中的L2桥转发表被配置为将客户端的源MAC地址与至少标识至少目的地接口的信息 用于将客户端数据业务引导回与第一网络元件相关联的子网。 然后转发第一帧。 在一个实施例中,尽管可以使用任何方便的隧道机制,但是业务通过GRE封装隧道被引导回到与第一网络元件相关联的子网。 根据另一特征,在外部接入点处缓存的给定信息被用于使得漫游客户端能够在配置L2网桥转发表之前或期间继续无缝地接收入站流量(即,在任何出站流量实际上从 客户端)。