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1.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：US08027399B2
公开(公告)日：2011-09-27
申请号：US12855548
申请日：2010-08-12
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：US07418046B2
公开(公告)日：2008-08-26
申请号：US11022146
申请日：2004-12-22
CPC分类号： H04L25/0204 , H04L25/0212 , H04L25/0226 , H04L27/261
摘要： Each transmitter is assigned a time-only pilot code, a frequency-only pilot code, or a time-frequency pilot code to use for pilot transmission. The pilot codes may be pseudo-random, orthogonal, and/or cyclic-shift codes. To obtain a channel estimate for a transmitter using a time-frequency pilot code composed of a time-only code and a frequency-only code, a receiver multiplies a set of received symbols for each symbol period with a set of code values for the frequency-only code to obtain a set of detected symbols and performs an IDFT on the set of detected symbols to obtain an initial impulse response estimate. The receiver performs code matching on multiple initial impulse response estimates derived for multiple symbol periods with the time-only code to obtain a final impulse response estimate for the desired transmitter. The receiver retains the first L channel taps and zeroes out remaining channel taps, where L is the expected channel length.
摘要翻译： 为每个发射机分配一个仅时间导频码，仅频率导频码或用于导频传输的时频导频码。 导频码可以是伪随机，正交和/或循环移位码。 为了使用由时间唯一码和仅频率码构成的时频导频码来获得用于发射机的信道估计，接收机将用于每个符号周期的一组接收符号与频率的一组码值相乘 - 获得一组检测符号的代码，并对检测符号集合执行IDFT以获得初始脉冲响应估计。 接收机对具有多个符号周期的多个初始脉冲响应估计执行码匹配，其中仅使用时间码来获得所需发射机的最终脉冲响应估计。 接收器保留第一个L个通道抽头，并将剩余的通道抽头置零，其中L是预期的通道长度。
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公开(公告)号：US07145940B2
公开(公告)日：2006-12-05
申请号：US10890718
申请日：2004-07-13
CPC分类号： H04L25/0226 , H04B7/0452 , H04B7/0684 , H04L27/2613
摘要： Efficient pilot transmission schemes for multi-antenna communication systems are described. In general, MISO receivers prefer a pilot transmitted in one spatial direction, and MIMO receivers typically require a pilot transmitted in different spatial directions. In one pilot transmission scheme, a first set of T scaled pilot symbols is generated with a first training vector and transmitted (e.g., continuously) from T transmit antennas, where T>1. If MIMO receiver(s) are to be supported by the system, then at least T−1 additional sets of T scaled pilot symbols are generated with at least T−1 additional training vectors and transmitted from the T transmit antennas. The training vectors are for different (e.g., orthogonal) spatial directions. Each MISO receiver can estimate its MISO channel based on the first set of scaled pilot symbols. Each MIMO receiver can estimate its MIMO channel based on the first and additional sets of scaled pilot symbols.
摘要翻译： 描述了用于多天线通信系统的有效导频传输方案。 通常，MISO接收机优选在一个空间方向上发送的导频，并且MIMO接收机通常需要在不同空间方向上发送的导频。 在一个导频传输方案中，用第一训练向量生成第一组T比例导频符号，并从T个发射天线发射（例如，连续地），其中T> 1。 如果MIMO接收机将被系统支持，则至少T-1个额外的T比例导频符号集合至少产生T-1个附加训练向量并从T个发射天线发射。 训练矢量用于不同的（例如正交的）空间方向。 每个MISO接收机可以基于第一组缩放的导频符号来估计其MISO信道。 每个MIMO接收机可以基于第一个和额外的缩放导频符号集来估计其MIMO信道。
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公开(公告)号：US08064424B2
公开(公告)日：2011-11-22
申请号：US11213463
申请日：2005-08-26
申请人： Sharad Deepak Sambhwani , Dhananjay Ashok Gore , Avneesh Agrawal , Arak Sutivong , Alexei Gorokhov
发明人： Sharad Deepak Sambhwani , Dhananjay Ashok Gore , Avneesh Agrawal , Arak Sutivong , Alexei Gorokhov
IPC分类号： H04B7/216
CPC分类号： H04J13/0048 , H04J13/18
摘要： Systems and methodologies are described that facilitate increasing system capacity in a code-limited WCDMA (e.g., TDD, FDD, . . . ) wireless communication environment. According to one aspect, a larger code space can be defined by introducing multiple code clusters within a sector, wherein each cluster has a unique scrambling code. Codes within a cluster can have orthogonal Walsh sequences that can be assigned to user devices to facilitate communicating over a wireless network and can overlap with codes in another cluster. The unique scrambling code assigned to each cluster can ensure that duplicate Walsh sequences in another cluster in the same sector appear as a pseudo-noise codes.
摘要翻译： 描述了在有限的WCDMA（例如，TDD，FDD，...）无线通信环境中增加系统容量的系统和方法。 根据一个方面，可以通过在扇区内引入多个码集来定义更大的码空间，其中每个群集具有唯一的扰码。 群集内的代码可以具有可被分配给用户设备的正交沃尔什序列，以便于通过无线网络进行通信并且可以与另一个群集中的代码重叠。 分配给每个簇的唯一扰码可以确保同一扇区中另一个簇中的重复沃尔什序列显示为伪噪声码。
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公开(公告)号：US09088384B2
公开(公告)日：2015-07-21
申请号：US11511735
申请日：2006-08-28
IPC分类号： G11B17/04 , H04B7/216 , H04B1/00 , H04B7/02 , H04J13/10 , H04L25/03 , H04B1/713 , H04L5/00 , H04L25/02
CPC分类号： H04J13/102 , H04B1/713 , H04L5/0026 , H04L5/0051 , H04L25/0204 , H04L25/0226 , H04L25/03866
摘要： Pilot symbols transmitted from different sectors of a same base station are multiplied with a same cell specific scrambling code and a first code having low cross correlation and second codes having low cross correlation. The second code is constant over the length of the first code, but may vary for repetitions of the first code.
摘要翻译： 从相同基站的不同扇区发送的导频符号与相同的小区特定扰码和具有低互相关的第一码和具有低互相关的第二码相乘。 第二个代码在第一个代码的长度上是恒定的，但是对于第一个代码的重复可能会有所不同。
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公开(公告)号：US08693405B2
公开(公告)日：2014-04-08
申请号：US11261837
申请日：2005-10-27
IPC分类号： H04B7/00
CPC分类号： H04W72/06 , H04B1/713 , H04B7/026 , H04L5/0023 , H04L5/0037 , H04L5/0044 , H04L5/023
摘要： A method for allocating resources in a wireless communications environment comprises receiving a mapping between a first hop-port and frequency range, and determining whether to map a second access terminal to a second hop-port that is mapped to at least the same frequency range during a substantially similar instance in time, the determination made as a function of characteristics relating to a first access terminal associated with the first hop-port. The method can further include determining that the first access terminal is a candidate for employing Space-Division Multiple Access (SDMA), and mapping the second-hop port and associating the second access terminal with the second hop-port when the second access terminal is also a candidate for employing SDMA.
摘要翻译： 一种用于在无线通信环境中分配资源的方法包括：接收第一跳跃端口和频率范围之间的映射，以及确定是否将第二接入终端映射到映射到至少相同频率范围的第二跳频端口 基本相似的时间实例，根据与与第一跳跃端口相关联的第一接入终端的特性的函数进行确定。 该方法还可以包括确定第一接入终端是采用空分多址（SDMA）的候选者，并且当第二接入终端是第二接入终端时，映射第二跳接口并将第二接入终端与第二跳接口相关联 也是采用SDMA的候选人。
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7.发明授权Iterative channel and interference estimation with dedicated pilot tones for OFDMA 有权用于OFDMA的专用导频音的迭代信道和干扰估计公开(公告)号：US07830976B2
公开(公告)日：2010-11-09
申请号：US11182235
申请日：2005-07-15
IPC分类号： H04B7/02
CPC分类号： H04L25/0236 , H04L5/0007 , H04L5/0048 , H04L5/023 , H04L25/0248 , H04L27/2647
摘要： Estimation of channel characteristics and interference level in a time-varying multi-carrier multi-user systems is carried out concurrently. To perform the estimation, a multitude of data symbols and dedicated pilot symbols are transmitted over the channel. Next, an initial estimate value is selected for the interference level. The initial estimate value for the interference level is used together with the received pilot symbols to provide a first estimate of the channel. The first estimate of the channel is used to determine a new updated value for the interference level, which in turn, is used to update the value of the first estimate of the channel iteratively. The iterations continue until the iteratively updated values of the interference level and channel satisfy predefined limits. The data symbols and the final updated value of the channel are subsequently used to provide a second estimate for the channel.
摘要翻译： 并行执行时变多载波多用户系统中的信道特性和干扰电平的估计。 为了执行估计，通过信道发送多个数据符号和专用导频符号。 接下来，针对干扰电平选择初始估计值。 干扰电平的初始估计值与接收到的导频符号一起使用以提供信道的第一估计。 信道的第一估计用于确定用于干扰电平的新的更新值，其又用于迭代地更新信道的第一估计值。 迭代继续，直到干扰电平和通道的迭代更新值满足预定义的限制。 随后使用数据符号和信道的最终更新值来提供信道的第二估计。
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8.发明授权Frequency domain filtering to improve channel estimation in multicarrier systems 失效频域滤波以改善多载波系统中的信道估计公开(公告)号：US07616711B2
公开(公告)日：2009-11-10
申请号：US11022360
申请日：2004-12-22
CPC分类号： H04L27/2647 , H04L5/0007 , H04L5/0048 , H04L5/006 , H04L25/022 , H04L25/0226 , H04L25/023
摘要： A channel estimation system comprises a filtering component that selectively scales a plurality of carriers as a function of location of the plurality of carriers within a frequency band, wherein the plurality of carriers comprises at least one data carrier and at least one pilot carrier. A component thereafter extrapolates an observation from the at least one pilot carrier, wherein a channel is estimated as a function of the extrapolated observation. The scaling of the carriers facilitates reducing a flooring effect associated with channel estimation. The filtering component can be employed at a transmitter and/or at a receiver, and can be activated and/or deactivated as a function of a sensed data packet type.
摘要翻译： 信道估计系统包括：滤波部件，其选择性地按照频带内的多个载波的位置来缩放多个载波，其中所述多个载波包括至少一个数据载波和至少一个导频载波。 然后，组件从至少一个导频载波外推观测，其中，估计信道作为外推观测的函数。 载波的缩放有助于减少与信道估计相关的地板效应。 滤波组件可以在发射机和/或接收机处采用，并且可以作为感测数据分组类型的功能被激活和/或去激活。
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公开(公告)号：US20080112495A1
公开(公告)日：2008-05-15
申请号：US11873375
申请日：2007-10-16
IPC分类号： H04K1/10
CPC分类号： H04L25/0204 , H04L25/0212 , H04L25/0226 , H04L27/261
摘要： Each transmitter is assigned a time-only pilot code, a frequency-only pilot code, or a time-frequency pilot code to use for pilot transmission. The pilot codes may be pseudo-random, orthogonal, and/or cyclic-shift codes. To obtain a channel estimate for a transmitter using a time-frequency pilot code composed of a time-only code and a frequency-only code, a receiver multiplies a set of received symbols for each symbol period with a set of code values for the frequency-only code to obtain a set of detected symbols and performs an IDFT on the set of detected symbols to obtain an initial impulse response estimate. The receiver performs code matching on multiple initial impulse response estimates derived for multiple symbol periods with the time-only code to obtain a final impulse response estimate for the desired transmitter. The receiver retains the first L channel taps and zeroes out remaining channel taps, where L is the expected channel length.
摘要翻译： 为每个发射机分配一个仅时间导频码，仅频率导频码或用于导频传输的时频导频码。 导频码可以是伪随机，正交和/或循环移位码。 为了使用由时间唯一码和仅频率码构成的时频导频码来获得用于发射机的信道估计，接收机将用于每个符号周期的一组接收符号与频率的一组码值相乘 - 获得一组检测符号的代码，并对检测符号集合执行IDFT以获得初始脉冲响应估计。 接收机对具有多个符号周期的多个初始脉冲响应估计执行码匹配，其中仅使用时间码来获得所需发射机的最终脉冲响应估计。 接收器保留第一个L个通道抽头，并将剩余的通道抽头置零，其中L是预期的通道长度。
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10.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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