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    Method and apparatus for channel estimation for multicarrier systems
    2.
    发明授权
    Method and apparatus for channel estimation for multicarrier systems 失效
    多载波系统信道估计方法和装置

    公开(公告)号：US06327314B1

    公开(公告)日：2001-12-04

    申请号：US09089862

    申请日：1998-06-03

    申请人： Leonard Joseph Cimini, Jr. ,  Ye Li ,  Nelson Ray Sollenberger

    发明人： Leonard Joseph Cimini, Jr. ,  Ye Li ,  Nelson Ray Sollenberger

    IPC分类号： H03D100

    CPC分类号： G01S3/72 ,  H01Q3/2605 ,  H04L25/022 ,  H04L27/2647

    摘要： A method and apparatus provide channel estimation for multicarrier systems. A minimum mean-square-error (MMSE) channel estimator makes full use of time-and frequency-domain correlations of the frequency response of time-varying dispersive fading channels. A robust channel estimator that is insensitive to the channel statistics is provided. The robust channel estimator can significantly improve the performance of a multicarrier system such as an orthogonal frequency division multiplexing (OFDM) modulation system in a rapid dispersive fading channel. In addition, the estimation process can employ a new reference generator which can select the source of the reference signal as being a decoded or undecoded signal depending on the correction success rate of the decoder.

    摘要翻译： 一种方法和装置为多载波系统提供信道估计。 最小均方误差（MMSE）信道估计器充分利用时变色散衰落信道的频率响应的时域和频域相关性。 提供对信道统计不敏感的鲁棒信道估计器。 鲁棒的信道估计器可以显着改善快速色散衰落信道中的诸如正交频分复用（OFDM）调制系统的多载波系统的性能。 此外，估计处理可以使用新的参考生成器，其可以根据解码器的校正成功率将参考信号的源选择为解码或未解码的信号。

    Method and system for reduction of peak-to-average power ratio of transmission signals comprising overlapping waveforms
    4.
    发明授权
    Method and system for reduction of peak-to-average power ratio of transmission signals comprising overlapping waveforms 有权
    用于降低包括重叠波形的传输信号的峰值与平均功率比的方法和系统

    公开(公告)号：US08064853B2

    公开(公告)日：2011-11-22

    申请号：US12605264

    申请日：2009-10-23

    申请人： Leonard Joseph Cimini, Jr. ,  Nelson Ray Sollenberger

    发明人： Leonard Joseph Cimini, Jr. ,  Nelson Ray Sollenberger

    IPC分类号： H04J13/00 ,  H04B1/04

    CPC分类号： H04L27/2623 ,  H04B1/0475 ,  H04B7/2628 ,  H04B2201/70706 ,  H04L27/2614 ,  H04L27/2621

    摘要： The present invention provides a method and system for reducing the peak to average power ratio (PAP) of a signal with low computational complexity. According to one embodiment, the present invention is applied to reduce the PAP of an OFDM signal. According to an alternative embodiment, the present invention, is applied to reduce the PAP of a CDMA signal. Rather than seeking the optimum solution, which involves significant computational complexity, the present invention provides for a number of sub-optimal techniques for reducing the PAP of an OFDM signal but with much lower computational complexity. In particular, according to one embodiment utilizing the PTS approach, an iterative technique is used to assign phase factors to each of a set of partial transmit sequences from a set of possible phase factors. Experimental results using the iterative technique showed only a slight degradation (1 dB) from the optimal approach using the same number of subblocks and subcarriers. In an alternative embodiment, which avoids feedback required by the iterative approach, a sequence of phase factors are generated randomly and assigned to each of a set of partial transmit sequences. This procedure is repeated for a pre-determined number of trials and the random sequence generating the lowest PAP is selected. In a third embodiment, a set of phase factors is generated using a structured sequence such as a Walsh sequence.

    摘要翻译： 本发明提供一种降低计算复杂度低的信号的峰均功率比（PAP）的方法和系统。 根据一个实施例，本发明应用于减少OFDM信号的PAP。 根据替代实施例，本发明被应用于减少CDMA信号的PAP。 本发明不是寻求涉及大量计算复杂度的最佳解决方案，而是提供了许多用于减少OFDM信号的PAP但具有低得多的计算复杂度的次优技术。 特别地，根据利用PTS方法的一个实施例，使用迭代技术来从一组可能的相位因子将相位因子分配给一组部分发送序列中的每一个。 使用迭代技术的实验结果显示，使用相同数量的子块和子载波的最优方法仅显示轻微的退化（1 dB）。 在避免迭代方法所需的反馈的替代实施例中，随机产生一系列相位因子并分配给一组部分发送序列中的每一个。 对于预定数量的试验重复该过程，并且选择产生最低PAP的随机序列。 在第三实施例中，使用诸如沃尔什序列的结构化序列来生成一组相位因子。

    Method for estimating time and frequency offset in an OFDM system
    6.
    发明授权
    Method for estimating time and frequency offset in an OFDM system 有权
    用于估计OFDM系统中的时间和频率偏移的方法

    公开(公告)号：US07990839B2

    公开(公告)日：2011-08-02

    申请号：US11982121

    申请日：2007-10-31

    申请人： Leonard Joseph Cimini, Jr. ,  Bruce Edwin McNair

    发明人： Leonard Joseph Cimini, Jr. ,  Bruce Edwin McNair

    IPC分类号： H04J11/00 ,  H04L27/06 ,  H04L27/28

    CPC分类号： H04L27/2655 ,  H04L27/2657 ,  H04L27/2662 ,  H04L27/2679

    摘要： A receiver that employs inherent characteristics of frequency domain representation of the data symbols. By computing a differential-in-frequency function across a large number of OFDM tones, robust estimates of time and frequency offset are obtained. The obtained time and frequency estimates provide control to sampling and frequency offset elements that are interposed between the reliever input and subsequent receiver stages.

    摘要翻译： 采用数据符号的频域表示的固有特性的接收机。 通过计算大量OFDM音调的频率差分函数，可获得时间和频率偏移的鲁棒估计。 获得的时间和频率估计提供对插入在缓冲器输入和后续接收器级之间的采样和频率偏移元件的控制。

    Method and system for reducing of peak-to-average power ratio of transmission signals comprising overlapping waveforms
    7.
    发明授权
    Method and system for reducing of peak-to-average power ratio of transmission signals comprising overlapping waveforms 有权
    用于降低包括重叠波形的传输信号的峰值与平均功率比的方法和系统

    公开(公告)号：US06556557B1

    公开(公告)日：2003-04-29

    申请号：US09324487

    申请日：1999-06-02

    申请人： Leonard Joseph Cimini, Jr. ,  Nelson Ray Sollenberger

    发明人： Leonard Joseph Cimini, Jr. ,  Nelson Ray Sollenberger

    IPC分类号： H04B7216

    CPC分类号： H04L27/2623 ,  H04B1/0475 ,  H04B7/2628 ,  H04B2201/70706 ,  H04L27/2614 ,  H04L27/2621

    摘要： The present invention provides a method and system for reducing the peak to average power ratio (PAP) of a signal with low computational complexity. According to one embodiment, the present invention is applied to reduce the PAP of an OFDM signal. According to an alternative embodiment, the present invention is applied to reduce the PAP of a CDMA signal. Rather than seeking the optimum solution, which involves significant computational complexity, the present invention provides for a number of sub-optimal techniques for reducing the PAP of an OFDM signal but with much lower computational complexity. In particular, according to one embodiment utilizing the PTS approach, an iterative technique is used to assign phase factors to each of a set of partial transmit sequences from a set of possible phase factors. Experimental results using the iterative technique showed only a slight degradation (1 dB) from the optimal approach using the same number of subblocks and subcarriers. In an alternative embodiment, which avoids feedback required by the iterative approach, a sequence of phase factors are generated randomly and assigned to each of a set of partial transmit sequences. This procedure is repeated for a pre-determined number of trials and the random sequence generating the lowest PAP is selected. In a third embodiment, a set of phase factors is generated using a structured sequence such as a Walsh sequence.

    摘要翻译： 本发明提供一种降低计算复杂度低的信号的峰均功率比（PAP）的方法和系统。 根据一个实施例，本发明应用于减少OFDM信号的PAP。 根据替代实施例，本发明被应用于减少CDMA信号的PAP。 本发明不是寻求涉及大量计算复杂度的最佳解决方案，而是提供了许多用于减少OFDM信号的PAP但具有低得多的计算复杂度的次优技术。 特别地，根据利用PTS方法的一个实施例，使用迭代技术来从一组可能的相位因子将相位因子分配给一组部分发送序列中的每一个。 使用迭代技术的实验结果显示，使用相同数量的子块和子载波的最优方法仅显示轻微的退化（1 dB）。 在避免迭代方法所需的反馈的替代实施例中，随机产生一系列相位因子并分配给一组部分发送序列中的每一个。 对于预定数量的试验重复该过程，并且选择产生最低PAP的随机序列。 在第三实施例中，使用诸如沃尔什序列的结构化序列来生成一组相位因子。