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11.发明授权Pilot transmission and channel estimation for an OFDM system with excess delay spread 有权具有超延迟扩展的OFDM系统的导频传输和信道估计公开(公告)号：US07339999B2
公开(公告)日：2008-03-04
申请号：US10821706
申请日：2004-04-09
CPC分类号： H04L25/0226 , H04L5/0007 , H04L5/0048 , H04L25/0202 , H04L25/0212 , H04L27/2607 , H04L27/2647
摘要： Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one channel estimation technique, first and second groups of received pilot symbols are obtained for first and second pilot subband sets, respectively, and used to derive first and second frequency response estimates, respectively. First and second impulse response estimates are derived based on the first and second frequency response estimates, respectively, and used to derive a third impulse response estimate having more taps than the number of pilot subbands in either set.
摘要翻译： 描述了具有超延迟扩展的OFDM系统的导频传输和信道估计技术。 为了减轻多余的延迟扩展的有害影响，导频子带的数量大于循环前缀长度。 这种“过采样”可以通过在每个符号周期中使用更多的导频子带或在不同的符号周期内使用不同的导频子带集来实现。 在一个信道估计技术中，分别为第一和第二导频子带集获得第一组和第二组接收导频符号，并分别用于导出第一和第二频率响应估计。 基于第一和第二频率响应估计分别导出第一和第二脉冲响应估计，并且用于导出具有比两组中的导频子带数更多的抽头的第三脉冲响应估计。
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公开(公告)号：US08484272B2
公开(公告)日：2013-07-09
申请号：US11022537
申请日：2004-12-22
IPC分类号： G06F17/14
CPC分类号： H04L5/0048 , H04L5/0007 , H04L5/0044 , H04L25/03834 , H04L27/0008 , H04L27/2607 , H04L27/2626 , H04L27/2647
摘要： To transmit a multi-carrier signal, a transmitter provides zero symbols for guard subbands, performs OFDM modulation, and filters the resultant time-domain samples with a pulse shaping filter. To transmit a single-carrier signal, the transmitter partitions the single-carrier signal into segments. Each segment contains up to K samples and is padded, if needed, to the length of an OFDM symbol. Each padded segment is transformed from the time domain to the frequency domain to generate a corresponding frequency-domain segment with K symbols. For each frequency-domain segment, the symbols corresponding to the guard subbands are set to zero. Each frequency-domain segment is then transformed from the frequency domain to the time domain to generate a corresponding time-domain segment. A cyclic prefix may or may not be appended to each time-domain segment. Each time-domain segment is filtered with the same pulse shaping filter to generate an output waveform for the single-carrier signal.
摘要翻译： 为了发送多载波信号，发射机为保护子带提供零符号，执行OFDM调制，并用脉冲整形滤波器对合成的时域采样进行滤波。 为了发送单载波信号，发射机将单载波信号分割成段。 每个段包含多达K个样本，并且如果需要，则填充到OFDM符号的长度。 每个填充段从时域变换到频域，以产生具有K个符号的对应的频域段。 对于每个频域段，对应于保护子带的符号被设置为零。 然后将每个频域段从频域变换到时域以产生对应的时域段。 循环前缀可以附加到每个时域段，也可以不附加到每个时域段。 每个时域分段用相同的脉冲整形滤波器滤波，以产生单载波信号的输出波形。
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公开(公告)号：US08339930B2
公开(公告)日：2012-12-25
申请号：US11405831
申请日：2006-04-17
IPC分类号： H04J11/00
CPC分类号： H04B1/69 , H04L5/0007 , H04L5/0048 , H04L25/0226 , H04L25/0232 , H04L27/2647
摘要： Techniques to perform channel estimation with pilot weighting are described. A receiver receives at least one transmission symbol for a pilot transmitted by a transmitter. Each transmission symbol may be generated with a single-carrier multiplexing scheme (e.g., IFDMA or LFDMA) or a multi-carrier multiplexing scheme (e.g., OFDMA). The receiver processes each received transmission symbol and obtains received pilot values. The receiver may derive an interference estimate based on the received pilot values and may estimate the reliability of the received pilot values based on the interference estimate. The receiver determines weights for the received pilot values based on the transmitted pilot values, the estimated reliability of the received pilot values, and/or other information. The receiver derives a channel estimate based on the received pilot values and the weights. The receiver then performs data detection (e.g., equalization) on received data values with the channel estimate.
摘要翻译： 描述了使用导频加权来执行信道估计的技术。 接收机接收由发射机发送的导频的至少一个传输符号。 可以使用单载波复用方案（例如，IFDMA或LFDMA）或多载波复用方案（例如，OFDMA）生成每个传输符号。 接收机处理每个接收的传输符号并获得接收到的导频值。 接收机可以基于接收到的导频值导出干扰估计，并且可以基于干扰估计来估计接收到的导频值的可靠性。 接收机基于发送的导频值，接收到的导频值的估计可靠性和/或其他信息来确定接收到的导频值的权重。 接收器根据接收到的导频值和权重导出信道估计。 然后，接收机对具有信道估计的接收数据值执行数据检测（例如，均衡）。
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公开(公告)号：US08085875B2
公开(公告)日：2011-12-27
申请号：US11128976
申请日：2005-05-13
IPC分类号： H04L27/00
CPC分类号： H04L25/0226 , H04L5/0007 , H04L5/005 , H04L5/0051 , H04L5/006
摘要： Dynamic resource allocation systems, apparatus, and methods are disclosed for selectively improving the ability of a receiver to determine a channel estimate in an Orthogonal Frequency Division Multiple Access (OFDMA) system. A wireless communication system can use a common pilot channel configuration to aid channel estimation in one or more receivers in communication with the system. A receiver in communication with the system may be unable to demodulate received data due to an inaccurate channel estimate. The receiver can communicate to a transmitter in the system a request for additional channel estimation resources. The wireless communication system can provide additional channel estimation resources by inserting dedicated pilot channels into one or more of the frequencies allocated to symbols for the receiver. If the receiver is still unable to demodulate received data, the wireless communication system can incrementally insert additional pilot channels in the symbol associated with the receiver.
摘要翻译： 公开了动态资源分配系统，装置和方法，用于选择性地提高接收机在正交频分多址（OFDMA）系统中确定信道估计的能力。 无线通信系统可以使用公共导频信道配置来辅助与系统通信的一个或多个接收机中的信道估计。 与系统通信的接收机可能由于不准确的信道估计而无法解调所接收的数据。 接收机可以向系统中的发射机通信另外的信道估计资源的请求。 无线通信系统可以通过将专用导频信道插入分配给接收机的符号的一个或多个频率来提供额外的信道估计资源。 如果接收机仍然不能解调所接收的数据，则无线通信系统可以递增地在与接收机相关联的符号中插入附加的导频信道。
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15.发明授权Pilot transmission and channel estimation for an OFDM system with excess delay spread 有权具有超延迟扩展的OFDM系统的导频传输和信道估计公开(公告)号：US08537908B2
公开(公告)日：2013-09-17
申请号：US12041510
申请日：2008-03-03
IPC分类号： H04K1/10
CPC分类号： H04L25/0226 , H04L5/0007 , H04L5/0048 , H04L25/0202 , H04L25/0212 , H04L27/2607 , H04L27/2647
摘要： Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one example, a first set of pilot subbands may be received in a first symbol period, and a second set of pilot subbands may be received in a second symbol period. The first set of pilot subbands and the second set of pilot subbands may be staggered in frequency.
摘要翻译： 描述了具有超延迟扩展的OFDM系统的导频传输和信道估计技术。 为了减轻多余的延迟扩展的有害影响，导频子带的数量大于循环前缀长度。 这种“过采样”可以通过在每个符号周期中使用更多的导频子带或在不同的符号周期内使用不同的导频子带集来实现。 在一个示例中，可以在第一符号周期中接收第一组导频子带，并且可以在第二符号周期中接收第二组导频子带。 第一组导频子带和第二组导频子带可以以频率交错。
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16.发明申请PILOT TRANSMISSION AND CHANNEL ESTIMATION FOR AN OFDM SYSTEM WITH EXCESS DELAY SPREAD 有权具有超越延迟扩展的OFDM系统的导频传输和信道估计公开(公告)号：US20100303165A1
公开(公告)日：2010-12-02
申请号：US12855548
申请日：2010-08-12
IPC分类号： H04L27/28
CPC分类号： H04L25/0226 , H04L5/0007 , H04L5/0048 , H04L25/0202 , H04L25/0212 , H04L27/2607 , H04L27/2647
摘要： Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one example, a first set of pilot subands may be received in a first symbol period, and a second set of pilot subands may be received in a second symbol period. The first set of pilot subands and the second set of pilot subbands may be staggered in frequency.
摘要翻译： 描述了具有超延迟扩展的OFDM系统的导频传输和信道估计技术。 为了减轻多余的延迟扩展的有害影响，导频子带的数量大于循环前缀长度。 这种“过采样”可以通过在每个符号周期中使用更多的导频子带或在不同的符号周期内使用不同的导频子带集来实现。 在一个示例中，可以在第一符号周期中接收第一组导频子，并且可以在第二符号周期中接收第二组导频子。 第一组导频子区和第二组导频子带可能会频率交错。
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17.发明申请PILOT TRANSMISSION AND CHANNEL ESTIMATION FOR AN OFDM SYSTEM WITH EXCESS DELAY SPREAD 有权具有超越延迟扩展的OFDM系统的导频传输和信道估计公开(公告)号：US20080152033A1
公开(公告)日：2008-06-26
申请号：US12041510
申请日：2008-03-03
IPC分类号： H04L27/28
CPC分类号： H04L25/0226 , H04L5/0007 , H04L5/0048 , H04L25/0202 , H04L25/0212 , H04L27/2607 , H04L27/2647
摘要： Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one example, a first set of pilot subands may be received in a first symbol period, and a second set of pilot subands may be received in a second symbol period. The first set of pilot subands and the second set of pilot subbands may be staggered in frequency.
摘要翻译： 描述了具有超延迟扩展的OFDM系统的导频传输和信道估计技术。 为了减轻多余的延迟扩展的有害影响，导频子带的数量大于循环前缀长度。 这种“过采样”可以通过在每个符号周期中使用更多的导频子带或在不同的符号周期内使用不同的导频子带集来实现。 在一个示例中，可以在第一符号周期中接收第一组导频子，并且可以在第二符号周期中接收第二组导频子。 第一组导频子区和第二组导频子带可能会频率交错。
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公开(公告)号：US08619717B2
公开(公告)日：2013-12-31
申请号：US12690307
申请日：2010-01-20
申请人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
发明人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
IPC分类号： H04B7/00
CPC分类号： H04L1/0618 , H04B7/0417 , H04B7/0443 , H04B7/0465 , H04B7/0615 , H04B7/0891 , H04W52/34 , H04W52/42
摘要： A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas. The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.
摘要翻译： 可以传输可变数量的数据符号流的MIMO系统的速率自适应传输方案为每个数据符号流提供发射分集，并且充分利用系统的总发射功率和每个天线的全功率。 在一种方法中，接收至少一个数据符号流用于从多个天线发射。 每个数据符号流用对应于分配给该流的发射功率的量的相应权重进行缩放。 缩放的数据符号流与发射基矩阵相乘以为多个天线提供多个发射符号流。 定义发射基矩阵（例如，沃尔什 - 哈达玛矩阵或DFT矩阵），使得每个数据符号流从所有天线发送，并且每个发射符号流以（或接近）相关天线的全功率发射。
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公开(公告)号：US06873606B2
公开(公告)日：2005-03-29
申请号：US10367234
申请日：2003-02-14
申请人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
发明人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
IPC分类号： H04B7/00 , H04B7/005 , H04B7/04 , H04B7/06 , H04B7/08 , H04J99/00 , H04L1/00 , H04L1/06 , H04B1/02
CPC分类号： H04L1/0618 , H04B7/0417 , H04B7/0443 , H04B7/0465 , H04B7/0615 , H04B7/0891 , H04W52/34 , H04W52/42
摘要： A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas. The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.
摘要翻译： 可以传输可变数量的数据符号流的MIMO系统的速率自适应传输方案为每个数据符号流提供发射分集，并且充分利用系统的总发射功率和每个天线的全功率。 在一种方法中，接收至少一个数据符号流用于从多个天线发射。 每个数据符号流用对应于分配给该流的发射功率的量的相应权重进行缩放。 缩放的数据符号流与发射基矩阵相乘以为多个天线提供多个发射符号流。 定义发射基矩阵（例如，沃尔什 - 哈达玛矩阵或DFT矩阵），使得每个数据符号流从所有天线发送，并且每个发射符号流以（或接近）相关天线的全功率发射。
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公开(公告)号：US20050013239A1
公开(公告)日：2005-01-20
申请号：US10919698
申请日：2004-08-16
申请人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
发明人： Avneesh Agrawal , Rajiv Vijayan , Tamer Kadous
IPC分类号： H04B7/00 , H04B7/005 , H04B7/04 , H04B7/06 , H04B7/08 , H04J99/00 , H04L1/00 , H04L1/06 , H04J11/00 , H04Q7/00
CPC分类号： H04L1/0618 , H04B7/0417 , H04B7/0443 , H04B7/0465 , H04B7/0615 , H04B7/0891 , H04W52/34 , H04W52/42
摘要： A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas. The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.
摘要翻译： 可以传输可变数量的数据符号流的MIMO系统的速率自适应传输方案为每个数据符号流提供发射分集，并且充分利用系统的总发射功率和每个天线的全功率。 在一种方法中，接收至少一个数据符号流用于从多个天线发射。 每个数据符号流用对应于分配给该流的发射功率的量的相应权重进行缩放。 缩放的数据符号流与发射基矩阵相乘以为多个天线提供多个发射符号流。 定义发射基矩阵（例如，沃尔什 - 哈达玛矩阵或DFT矩阵），使得每个数据符号流从所有天线发送，并且每个发射符号流以（或接近）相关天线的全功率发射。
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