Method and apparatus for frequency synchronization in a digital transmission system
    1.
    发明授权
    Method and apparatus for frequency synchronization in a digital transmission system 有权
    数字传输系统中频率同步的方法和装置

    公开(公告)号:US07062282B2

    公开(公告)日:2006-06-13

    申请号:US10199203

    申请日:2002-07-19

    IPC分类号: H04B7/005 H04J1/00

    摘要: Frequency synchronization bursts are detected for a radio communication system such as a GSM cellular telephone network using a two stage correlation process. A first unit performs a first set of correlations to identify receipt of the frequency synchronization burst. A preliminary identification is declared when the moving average of the first set of correlations, normalized for received power, exceeds a threshold value for a number of contiguous samples. After a preliminary identification is made, a second unit performs a second set of correlations to confirm the detection of the frequency synchronization burst. The second correlations are preferably also normalized and confirmation of detection is declared when the normalized moving average of the second stage correlation exceeds a threshold value for a number of contiguous samples.

    摘要翻译: 对于诸如GSM蜂窝电话网络的无线电通信系统使用两阶段相关处理来检测频率同步突发。 第一单元执行第一组相关性以识别频率同步突发的接收。 当针对接收功率归一化的第一组相关性的移动平均值超过多个连续采样的阈值时,宣布初步识别。 在进行初步识别之后,第二单元执行第二组相关性以确认频率同步脉冲串的检测。 第二相关性优选地也被归一化,并且当第二级相关的归一化移动平均值超过多个连续采样的阈值时,声明检测的确认。

    Channel estimation in a wireless transmission system
    2.
    发明授权
    Channel estimation in a wireless transmission system 失效
    无线传输系统中的信道估计

    公开(公告)号:US07440524B2

    公开(公告)日:2008-10-21

    申请号:US10217934

    申请日:2002-08-13

    IPC分类号: H03D1/00 H04L27/06

    CPC分类号: H04L25/0228 H04L25/0212

    摘要: A GSM communication system uses a channel estimator to generate a channel impulse response estimate from received bursts. Preferred embodiments of such a system include a first correlation unit that uses N midamble bits to evaluate received signals and produce first correlation outputs over a wide search range. A positioning unit identifies candidate first correlation outputs having the best estimation quality within a sliding observation window and uses those outputs as the initial channel impulse response (CIR) estimate. The initial CIR is provided to a second correlation unit that block correlates M (greater than N) midamble bits to the received signal samples. The second correlation unit performs correlation stage by stage with compensation based on the initial and updated CIR to improve the channel estimation.

    摘要翻译: GSM通信系统使用信道估计器从接收的脉冲串产生信道脉冲响应估计。 这种系统的优选实施例包括第一相关单元,该第一相关单元使用N个中间码比特来评估接收的信号并且在宽的搜索范围上产生第一相关输出。 定位单元识别在滑动观察窗内具有最佳估计质量的候选第一相关输出,并使用这些输出作为初始信道脉冲响应(CIR)估计。 将初始CIR提供给第二相关单元,该第二相关单元将M(大于N)个中位码比特与接收信号样本相关。 第二相关单元根据初始和更新的CIR逐级执行相关性,以改善信道估计。