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    Apparatus and method for sampling frequency offset estimation and correction in a wireless communication system
    21.
    发明授权
    Apparatus and method for sampling frequency offset estimation and correction in a wireless communication system 失效
    在无线通信系统中采样频率偏移估计和校正的装置和方法

    公开(公告)号：US07177374B2

    公开(公告)日：2007-02-13

    申请号：US11312510

    申请日：2005-12-21

    申请人： Rohit V. Gaikwad ,  Rajendra T. Moorti

    发明人： Rohit V. Gaikwad ,  Rajendra T. Moorti

    IPC分类号： H04L27/22

    CPC分类号： H04L27/2657 ,  H04L27/2675 ,  H04L27/2679 ,  H04L2027/003 ,  H04L2027/0059 ,  H04L2027/0067 ,  H04L2027/0095

    摘要： A method is described for correcting sampling frequency offset (SFO) of a data packet in a communications system where carrier frequency (fc) and sampling frequency (fs) are driven by a common clock source. The method comprises, for each lth symbol in the data packet, estimating carrier frequency offset (CFO) in a received data packet. From the CFO estimate, an SFO estimate is derived, wherein the SFO is approximately equal to fs multiplied by said CFO estimate, and divided by fc. An SFO phase correction is generated according to the SFO estimate for each kth tone in a data stream. The SFO phase correction is then applied to each received data stream.

    摘要翻译： 描述了一种用于校正通信系统中的数据分组的采样频率偏移（SFO）的方法，其中驱动载波频率（f SUB）和采样频率（f> s） 由公共时钟源。 对于数据分组中的每个第l0个符号，该方法包括估计接收的数据分组中的载波频率偏移（CFO）。 根据CFO估计，导出SFO估计，其中SFO近似等于所述CFO估计的乘积，并除以f C c。 根据数据流中的每个第k个音调的SFO估计来生成SFO相位校正。 然后将SFO相位校正应用于每个接收到的数据流。

    Methods and systems for calibrating for gain and phase imbalance and local oscillator feed-through
    22.
    发明授权
    Methods and systems for calibrating for gain and phase imbalance and local oscillator feed-through 有权
    用于校准增益和相位不平衡以及本地振荡器馈通的方法和系统

    公开(公告)号：US07831220B2

    公开(公告)日：2010-11-09

    申请号：US11396632

    申请日：2006-04-04

    申请人： Joachim Hammerschmidt ,  Rajendra T. Moorti

    发明人： Joachim Hammerschmidt ,  Rajendra T. Moorti

    IPC分类号： H04B1/04

    CPC分类号： H04B17/21

    摘要： Methods and systems to calibrating a transmitter for I/Q imbalance and local oscillator feed-through include generating a test tone, frequency up-converting the test tone, monitoring one or more features of the up-converted test tone, and adjusting one or more features of the transmitter in response to the monitoring. The monitoring optionally includes monitoring a beating of the envelope of the up-converted test tone. In an embodiment, a first harmonic of the up-converted test tone is monitored for local oscillator feed-through (LOFT). Alternatively, baseband data inputs to the transmitter are disabled, and LOFT is measured by measuring power at the transmitter output. A second harmonic of the up-converted test tone is monitored for gain and phase imbalances. The adjusting optionally includes adjusting a gain imbalance, adjusting a phase imbalance, and/or adjusting DC offsets. The adjusting optionally includes an iterative refinement process. Such a refinement process optionally includes performing a first monitoring, applying a set of relatively coarse settings to the one or more features in the transmitter, monitoring the beating resulting from each of the coarse settings, selecting the coarse setting corresponding the smallest beating, applying a set of relatively fine settings centered around the selected coarse setting, wherein the fine settings are more closely related to one another than are the coarse settings, monitoring the beating resulting from each of the fine settings, and selecting the fine setting corresponding the smallest beating.

    摘要翻译： 用于校准发射机以用于I / Q不平衡和本地振荡器馈通的方法和系统包括产生测试音，上变频测试音，监测升高的测试音的一个或多个特征，以及调整一个或多个 变送器的功能响应监控。 该监视可选地包括监视向上转换的测试音的包络的跳动。 在一个实施例中，监视上转换的测试音的一次谐波用于本地振荡器馈通（LOFT）。 或者，对发射机的基带数据输入被禁用，并且通过测量发射机输出端的功率来测量LOFT。 监控上变频测试音的二次谐波，以获得增益和相位不平衡。 该调整可选地包括调整增益不平衡，调整相位不平衡和/或调整DC偏移。 调整可选地包括迭代细化过程。 这样的细化处理可选地包括执行第一监视，将一组相对粗略的设置应用于发射机中的一个或多个特征，监视由每个粗略设置产生的跳动，选择对应于最小跳动的粗略设置，应用 以选择的粗略设置为中心的相对精细设置的集合，其中精细设置比粗略设置彼此更紧密地相关，监视由每个精细设置产生的打击，并且选择对应于最小跳动的精细设置。