Frame synchronization and detection technique for a digital receiver
    4.
    发明授权
    Frame synchronization and detection technique for a digital receiver 有权
    数字接收机的帧同步和检测技术

    公开(公告)号:US06850582B2

    公开(公告)日:2005-02-01

    申请号:US10392115

    申请日:2003-03-17

    IPC分类号: H04J13/00 H04W84/14 H04L7/00

    CPC分类号: H04W84/14

    摘要: A system and method of frame synchronization and detection for use in a digital receiver within a communication system. The digital radio communication system includes a receiver for receiving a signal stream that includes data frames. Each frame includes an arbitrary data sequence and a unique word. A predetermined number of contiguous bits from the unique word are appended to the beginning of each data frame to identify the start of the data frame. The communication system comprises a sampling circuit for sampling symbol levels, a filter to implement the cross correlation of the received signal with the stored unique word, a threshold detector circuit to detect when frame synchronization is achieved as well as additional circuitry to refine the estimate from the threshold detection circuit. The design utilizes coherent demodulation. However, the design is equally applicable to non-coherent demodulation. In one embodiment, the sampling rate is assumed to be two samples per symbol. However, the functionality of the proposed design is not limited to two samples per symbol.

    摘要翻译: 用于通信系统内的数字接收机中的帧同步和检测的系统和方法。 数字无线电通信系统包括用于接收包括数据帧的信号流的接收机。 每帧包括任意数据序列和唯一字。 来自唯一字的预定数量的连续位被附加到每个数据帧的开头,以标识数据帧的开始。 通信系统包括用于对符号电平进行采样的采样电路,用于实现接收信号与存储的唯一字的互相关的滤波器,用于检测何时实现帧同步的阈值检测器电路以及用于从 阈值检测电路。 该设计采用相干解调。 然而,该设计同样适用于非相干解调。 在一个实施例中,假设采样率是每个符号的两个样本。 然而,所提出的设计的功能不限于每个符号两个样本。

    Joint maximum likelihood frame and timing estimation for a digital receiver
    5.
    发明授权
    Joint maximum likelihood frame and timing estimation for a digital receiver 失效
    数字接收机的联合最大似然帧和定时估计

    公开(公告)号:US06654432B1

    公开(公告)日:2003-11-25

    申请号:US09093414

    申请日:1998-06-08

    IPC分类号: H04L700

    摘要: A receiver for receiving a signal stream in a digital radio communication system. The signal stream includes data frames where each frame including a data signal sequence and a synchronizing signal sequence. The communication system synchronizes the receiver by employing the signal stream. The receiver includes a sampling circuit for sampling symbol levels in the synchronizing signal sequence and a synchronization subsystem. The synchronization subsystem utilizes a frame synchronization circuit, a dynamic interpolator and a decision-directed phase tracking mechanism for removing residual frequency and phase offsets. The synchronization subsystem also includes a threshold detection mechanism for comparing values derived from the sampled frame synchronization output with a predefined value which determines whether synchronization has occurred or not. The dynamic interpolator includes a circuit for generating the interpolation coefficients for timing and initial phase estimation, a maximum likelihood timing and phase estimator, and a data interpolation and decimation unit. The estimated timing offset and phase offset in the dynamic interpolator may change for each frame in the signal stream.

    摘要翻译: 一种用于在数字无线电通信系统中接收信号流的接收机。 信号流包括数据帧,其中每帧包括数据信号序列和同步信号序列。 通信系统通过采用信号流来同步接收机。 接收机包括用于对同步信号序列中的符号电平进行采样的采样电路和同步子系统。 同步子系统利用帧同步电路,动态内插器和用于去除残余频率和相位偏移的决策相位跟踪机制。 同步子系统还包括阈值检测机制,用于将从采样帧同步输出得到的值与预定义值进行比较,该预定义值确定是否已发生同步。 动态插值器包括用于产生用于定时和初始相位估计的内插系数的电路,最大似然定时和相位估计器以及数据插值和抽取单元。 动态内插器中的估计的定时偏移和相位偏移可以针对信号流中的每个帧而改变。

    Frame synchronization and detection technique for a digital receiver
    6.
    发明授权
    Frame synchronization and detection technique for a digital receiver 失效
    用于数字发射机的组合器电路和方法

    公开(公告)号:US06563856B1

    公开(公告)日:2003-05-13

    申请号:US09111812

    申请日:1998-07-08

    IPC分类号: H04B169

    CPC分类号: H04W84/14

    摘要: A combiner circuit and method for use in a digital transmitter within a communication system. The combiner circuit receives a number of signal streams that include data frames. Each frame includes an arbitrary data sequence and portions of a unique word. The combiner circuit comprises a plurality of digital preamble circuits which append a predetermined number of contiguous bits from the unique word to each data frame. The system utilizes a plurality of spreaders, shifters, and a summer to further modify the data stream for transmission.

    摘要翻译: 一种用于通信系统内的数字发射机的组合器电路和方法。 组合电路接收包括数据帧的多个信号流。 每帧包括任意数据序列和唯一字的部分。 组合器电路包括多个数字前置电路,其将来自唯一字的预定数量的连续位附加到每个数据帧。 该系统利用多个扩展器,移位器和加法器来进一步修改数据流以进行传输。

    Wireless multimedia carrier system
    7.
    发明授权
    Wireless multimedia carrier system 失效
    无线多媒体载体系统

    公开(公告)号:US06373827B1

    公开(公告)日:2002-04-16

    申请号:US08954217

    申请日:1997-10-20

    IPC分类号: H04B700

    CPC分类号: H04W84/14

    摘要: A system and method for communication of radio frequency (RF) signals over multimedia signal paths. The invention provides a wireless multimedia carrier (WMC) system capable of receiving a variety of standardized input signals, such as DS0/E0, T1/E1, T2/E2, and/or T3/E3 for transmission using RF channels. The WMC system selectively employs time division multiple access (TDMA) and/or code division multiple access (CDMA) technology. The WMC system transmits the various signal inputs using RF carriers, receives the transmitted signals, and converts the signals to the desired signaling scheme (standard) for forwarding to intended destinations.

    摘要翻译: 一种用于在多媒体信号路径上通信射频(RF)信号的系统和方法。 本发明提供一种无线多媒体载体(WMC)系统,其能够接收各种标准化的输入信号,例如用于使用RF信道传输的诸如DS0 / E0,T1 / E1,T2 / E2和/或T3 / E3。 WMC系统选择性地采用时分多址(TDMA)和/或码分多址(CDMA)技术。 WMC系统使用RF载波传输各种信号输入,接收发送的信号,并将信号转换为所需的信令方案(标准),以转发到预期的目的地。

    Non-data aided maximum likelihood based feedforward timing synchronization method
    9.
    发明授权
    Non-data aided maximum likelihood based feedforward timing synchronization method 有权
    基于非数据辅助最大似然的前馈定时同步方法

    公开(公告)号:US06768780B1

    公开(公告)日:2004-07-27

    申请号:US10060546

    申请日:2002-01-29

    IPC分类号: H04L700

    摘要: A system and method of timing estimation for use in a digital receiver within a communication system. An algorithm calculates the timing offset by evaluating the spectral component at the symbol clock frequency. The spectral component is generated using a nonlinearity operation. However, the maximum likelihood non-data-aided timing estimation equation reveals an alternative approximation for the logarithm of the hyperbolic cosine function present in the maximum likelihood equation, which offers a compromise between implementation complexity and variance performance. The estimated timing offset is then fed to a timing correction unit, which calculates the data samples corresponding to the sampling clock phase and removes the redundant samples. The ideal sampled signal is then forwarded to additional synchronization and functional units for further processing.

    摘要翻译: 用于在通信系统内的数字接收机中使用的定时估计的系统和方法。 算法通过评估符号时钟频率的频谱分量来计算定时偏移。 使用非线性运算产生频谱分量。 然而,最大似然非数据辅助定时估计方程揭示了最大似然方程中存在的双曲余弦函数的对数的替代近似,这提供了实现复杂度和方差性能之间的折中。 然后将估计的定时偏移馈送到定时校正单元,该定时校正单元计算对应于采样时钟相位的数据采样并且去除冗余采样。 然后将理想采样信号转发到附加的同步和功能单元进行进一步处理。

    Fetal heartbeat and uterine contraction
    10.
    发明授权
    Fetal heartbeat and uterine contraction 失效
    胎儿心跳和子宫收缩

    公开(公告)号:US5807271A

    公开(公告)日:1998-09-15

    申请号:US843233

    申请日:1997-04-14

    摘要: A monitoring system for monitoring detectable intermittent signals generated by a living being. In one embodiment, a pregnancy monitoring system monitors fetal heat beat and/or uterine contractions. A belt is configured to fit around the abdomen of a pregnant woman, with belt ends fastened together at her back. A number of sensors are mounted on the belt to detect fetal heartbeat and transmit corresponding electrical systems, preferably by wireless means, to a distant monitoring station. At least one uterine contraction sensor may also be mounted on the belt for detecting uterine contractions and transmitting a corresponding electrical signal to the monitoring station. In a second embodiment, an apron or jacket for placement in tight, uniform contact over the chest contains a plurality of sensors for detecting cardiac signals. These electrocardiographic signals are transmitted by a wireless transmitter to a distant, central monitoring system to produce a valid data signal at the remote station. Preferably, the belt and apron are in the form of a double-walled, spaced-sheet, receptacle that can be inflated, such as by an automatic air pump, to assure that the sensors are pressed tightly against the skin.

    摘要翻译: 用于监测由生物产生的可检测的间歇信号的监测系统。 在一个实施例中,怀孕监测系统监测胎儿热打击和/或子宫收缩。 皮带被配置成适合孕妇腹部,皮带末端固定在她的背部。 多个传感器安装在皮带上以检测胎儿心跳并将相应的电气系统优选地通过无线装置传输到远程监测站。 至少一个子宫收缩传感器也可以安装在皮带上用于检测子宫收缩并将相应的电信号传送到监测站。 在第二实施例中,用于放置在胸部上紧密均匀接触的围裙或护套包含用于检测心脏信号的多个传感器。 这些心电图信号由无线发射机传输到远程中央监控系统,以在远程站产生有效的数据信号。 优选地,皮带和皮圈是双层间隔片的容器的形式,其可以例如通过自动空气泵来充气,以确保传感器被紧紧地压靠在皮肤上。