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55 条记录 (耗时 0.016 秒)

    Dithering scheme using multiple antennas for OFDM systems
    51.
    发明授权
    Dithering scheme using multiple antennas for OFDM systems 有权
    OFDM系统使用多个天线的抖动方案

    公开(公告)号：US07529177B2

    公开(公告)日：2009-05-05

    申请号：US10229673

    申请日：2002-08-28

    申请人： Samel Celebi ,  Jie Song ,  Paul M. Yun

    发明人： Samel Celebi ,  Jie Song ,  Paul M. Yun

    IPC分类号： H04B1/00 ,  H04J11/00

    CPC分类号： H04B7/0682 ,  H04B7/0671 ,  H04B7/18517 ,  H04W52/34

    摘要： A ground-or roof-top-based repeater in an OFDM system uses multiple transmission antennas to retransmit satellite signals. By using multiple transmission antennas, multiple identical OFDM signals are transmitted. Dithering is performed by, using a phase of Rayleigh process generator, introducing a slight variable-frequency phase offset to all but one of the multiple identical transmitted OFDM signals, and thus the effective overall channel is more dynamic and provides spatial diversity to minimize long periods of fading in fading subchannels of the OFDM signals when the receiver is in a slow moving or stationary situation. To overcome the additional cancellation problem that can occur when two or more of the transmitting antennas are in a line-of-site position with the receiver and approximately the same distance from the receiver, a delay is deliberately introduced to make the delayed signal(s) appear to be reflected signals. This delay will not negatively impact the OFDM receiver performance as long as the delay is within the guard interval used in the OFDM process.

    摘要翻译： OFDM系统中的基于地面或屋顶的中继器使用多个发射天线来重发卫星信号。 通过使用多个发送天线，发送多个相同的OFDM信号。 通过使用瑞利处理发生器的相位对多个相同发射的OFDM信号中的除了一个之外的所有发射的OFDM信号引入轻微的可变频率相位偏移来进行抖动，因此有效整体信道更加动态，并提供空间分集以最小化长周期 当接收机处于缓慢移动或静止状态时，OFDM信号的衰落子信道中的衰落。 为了克服当两个或多个发射天线处于与接收机的位置位置并且与接收机大致相同距离时可能发生的额外的消除问题，故意引入延迟以使延迟的信号 ）似乎是反射信号。 只要延迟在OFDM过程中使用的保护间隔内，该延迟不会对OFDM接收机性能产生负面影响。

    Multi-channel receiver with improved AGC
    52.
    发明申请
    Multi-channel receiver with improved AGC 有权
    具有改进AGC的多通道接收器

    公开(公告)号：US20080159446A1

    公开(公告)日：2008-07-03

    申请号：US11648702

    申请日：2006-12-29

    申请人： Yhean-Sen Lai ,  Jie Song ,  Zhenyu Wang ,  Jinguo Yu

    发明人： Yhean-Sen Lai ,  Jie Song ,  Zhenyu Wang ,  Jinguo Yu

    IPC分类号： H04L27/08

    CPC分类号： H04L27/0008 ,  H03G3/3068 ,  H03G3/3078 ,  H04L27/2649

    摘要： An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, a primary AGC loop controls an analog sub-receiver adapted to simultaneously receive multiple signals. Multiple digital demodulators, coupled to the sub-receiver, demodulate the multiple received signals. Multiple secondary AGC loops, one for each received signal, compensate for variations in demodulated signal strengths caused by the primary AGC loop. A feed-forward AGC compensation technique generates scalar control values for scaling the demodulated signals before the demodulated signals are processed by the secondary AGC loops. This at least partially compensates for gain variations caused by the primary AGC, reducing received signal drop-outs before the secondary AGC loops can compensate for the gain variations. Because of systemic delays in the sub-receiver and the demodulators, the scalar control values are independently timed to be coincident with the variations in the demodulated signal strengths caused by the primary AGC loop.

    摘要翻译： 用于卫星广播应用的改进的多频道接收机等。 在示例性实施例中，主AGC环路控制适于同时接收多个信号的模拟子接收机。 耦合到子接收机的多个数字解调器解调多个接收信号。 多个次级AGC环路，每个接收信号一个补偿由主AGC环路引起的解调信号强度的变化。 前馈AGC补偿技术产生标量控制值，用于在解调后的信号由次级AGC环路处理之前缩放解调信号。 这至少部分地补偿由主AGC引起的增益变化，在次级AGC环路可以补偿增益变化之前减少接收信号丢失。 由于子接收机和解调器中的系统延迟，标量控制值被独立地定时以与由主AGC环路引起的解调信号强度的变化一致。

    Single path architecture & automatic gain control (SAGC) algorithm for low power SDARS receivers
    53.
    发明申请
    Single path architecture & automatic gain control (SAGC) algorithm for low power SDARS receivers 有权
    用于低功率SDARS接收机的单路径架构和自动增益控制（SAGC）算法

    公开(公告)号：US20070041481A1

    公开(公告)日：2007-02-22

    申请号：US11204631

    申请日：2005-08-16

    申请人： Robert Malkemes ,  Denis Orlando ,  Jie Song ,  Eric Zhong

    发明人： Robert Malkemes ,  Denis Orlando ,  Jie Song ,  Eric Zhong

    IPC分类号： H04L27/08

    CPC分类号： H03G3/3052 ,  H03G1/0088 ,  H04H20/22 ,  H04H40/90

    摘要： An automatic gain control (AGC) for use in a digital radio receiver that allows at least two types of input signal to be processed using a single receiver front end by supporting two modes of operation, each optimized for one particular signal type, and a third mode not optimized for either. The AGC enables smooth switching between the optimized modes of operation via the non-optimized mode. By measuring a difference in the strength between the demodulated signals, and comparing that to two preset values, the AGC which mode of operation to place the receiver in. Modes of operation are maintained by adjusting the gain of a variable gain amplifier (VGA), so that an appropriate incoming signal is amplified to a level that is suitable for an analogue-to-digital (ADC) converter. The AGC is compatible with existing satellite digital audio radio system (SDARS) transmission capabilities.

    摘要翻译： 一种在数字无线电接收机中使用的自动增益控制（AGC），其允许使用单个接收器前端来处理至少两种类型的输入信号，所述两个接收机前端通过支持针对一种特定信号类型优化的两种操作模式，以及第三种 模式未优化。 AGC可以通过非优化模式在优化的操作模式之间平滑切换。 通过测量解调信号之间的强度差，并将其与两个预设值进行比较，AGC将接收器放置在操作模式中。通过调节可变增益放大器（VGA）的增益来维持操作模式， 使得适当的输入信号被放大到适合于模数（ADC）转换器的电平。 AGC与现有的卫星数字音频无线电系统（SDARS）传输能力相兼容。