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    Real-time signal-to-noise ratio (SNR) estimation for BPSK and QPSK modulation using the active communications channel
    2.
    发明授权
    Real-time signal-to-noise ratio (SNR) estimation for BPSK and QPSK modulation using the active communications channel 失效
    使用有源通信信道进行BPSK和QPSK调制的实时信噪比（SNR）估计

    公开(公告)号：US07190741B1

    公开(公告)日：2007-03-13

    申请号：US10274756

    申请日：2002-10-21

    申请人： Robert M. Manning

    发明人： Robert M. Manning

    IPC分类号： H04L27/00 ,  H04Q1/20 ,  H04B1/10

    CPC分类号： H04B1/1027 ,  H04B17/336 ,  H04L1/206 ,  H04L27/2332

    摘要： Method and apparatus for estimating signal-to-noise ratio (SNR) γ of a composite input signal e(t) on a phase-modulated (e.g., BPSK) communications link. A first demodulator receives the composite input signal and a stable carrier signal and outputs an in-phase output signal; a second demodulator receives the composite input signal and a phase-shifted version of the carrier signal and outputs a quadrature-phase output signal; and phase error θE(t) contained within the composite input signal e(t) is calculated from the outputs of the first and second demodulators. A time series of statistically independent phase error measurements θE(t1), θE(t2), . . . , θE(tk) is obtained from the composite input signal subtending a time interval Δt=tk−t1 whose value is small enough such that γ(t) and σ(t) can be taken to be constant in Δt. A biased estimate γ* for the signal-to-noise ratio (SNR) γ of the composite input signal is calculated using maximum likelihood (ML) estimation techniques, and an unbiased estimate {circumflex over (γ)} for the signal-to-noise ratio (SNR) γ of the composite input signal is determined from the biased estimate γ*, such as by use of a look-up table.

    摘要翻译： 用于估计相位调制（例如，BPSK）通信链路上的复合输入信号e（t）的信噪比（SNR）γ的方法和装置。 第一解调器接收复合输入信号和稳定的载波信号并输出​​同相输出信号; 第二解调器接收复合输入信号和载波信号的相移版本并输出正交相输出信号; 并且从第一和第二解调器的输出计算包含在复合输入信号e（t）内的相位误差θE（t）。 统计学上独立的相位误差测量的时间序列θ（t）1（t）2（t 2） ，。 。 。 从对应于时间间隔Deltat = t k -t 1的复合输入信号获得θ（t）k i（t k） / SUB>其值足够小，使得在Deltat中可以使gamma（t）和sigma（t）保持恒定。 使用最大似然（ML）估计技术来计算复合输入信号的信噪比（SNR）γ的偏差估计γ*，以及对于信噪比估计技术的无偏估计（对于（γ） 根据偏置的估计γ*，例如通过使用查找表来确定复合输入信号的噪声比（SNR）γ。

    Distributed computing system with dual independent communications paths between computers and employing split tokens
    4.
    发明授权
    Distributed computing system with dual independent communications paths between computers and employing split tokens 失效
    分布式计算系统，具有计算机之间的双重独立通信路径，并采用分裂标记

    公开(公告)号：US4933936A

    公开(公告)日：1990-06-12

    申请号：US85833

    申请日：1987-08-17

    申请人： Robert D. Rasmussen ,  Robert M. Manning ,  Blair F. Lewis ,  Gary S. Bolotin ,  Richard S. Ward

    发明人： Robert D. Rasmussen ,  Robert M. Manning ,  Blair F. Lewis ,  Gary S. Bolotin ,  Richard S. Ward

    IPC分类号： G06F11/14 ,  H04L12/28 ,  H04L12/413

    CPC分类号： H04L12/28 ,  H04L12/4135

    摘要： This is a distributed computing system providing flexible fault tolerance; ease of software design and concurrency specification; and dynamic balance of the loads. The system comprises a plurality of computers each having a first input/output interface and a second input/output interface for interfacing to communications networks each second input/output interface including a bypass for bypassing the associated computer. A global communications network interconnects the first input/output interfaces for providing each computer the ability to broadcast messages simultaneously to the remainder of the computers. A meshwork communications network interconnects the second input/output interfaces providing each computer with the ability to establish a communications link with another of the computers bypassing the remainder of computers. Each computer is controlled by a resident copy of a common operating system. Communications between respective ones of computers is by means of split tokens each having a moving first portion which is sent from computer to computer and a resident second portion which is disposed in the memory of at least one of computer and wherein the location of the second portion is part of the first portion. The split tokens represent both functions to be executed by the computers and data to be employed in the execution of the functions. The first input/output interfaces each include logic for detecting a collision between messages and for terminating the broadcasting of a message whereby collisions between messages are detected and avoided.

    摘要翻译： 这是一种提供灵活容错的分布式计算系统; 易于软件设计和并发规范; 和负载的动态平衡。 该系统包括多个计算机，每个计算机具有第一输入/输出接口和用于与通信网络对接的第二输入/输出接口，每个第二输入/输出接口包括用于绕过相关计算机的旁路。 全球通信网络将第一输入/输出接口互连，以便为每台计算机提供与其余计算机同时广播消息的能力。 网状通信网络将第二输入/输出接口互连，为每台计算机提供与绕过其余计算机的其他计算机建立通信链路的能力。 每个计算机由常用操作系统的常驻副本控制。 各个计算机之间的通信是借助于每个具有从计算机发送到计算机的移动的第一部分的分割令牌和设置在计算机中的至少一个的存储器中的驻留的第二部分，并且其中第二部分的位置 是第一部分的一部分。 拆分标记表示要由计算机执行的功能和要在功能的执行中使用的数据。 第一输入/输出接口各自包括用于检测消息之间的冲突和用于终止消息的广播的逻辑，从而检测和避免消息之间的冲突。