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公开(公告)号：US20060209979A1
公开(公告)日：2006-09-21
申请号：US11261513
申请日：2005-10-31
申请人： Magnus Sandell , Darren McNamara , Steve Parker
发明人： Magnus Sandell , Darren McNamara , Steve Parker
IPC分类号： H04L1/02
CPC分类号： H04L27/2657 , H04L27/2675 , H04L2027/0032 , H04L2027/0065 , H04L2027/0075
摘要： The present invention relates to estimating and correcting for frequency offset errors in wireless receivers, and is particularly but not exclusively related to MIMO WLAN applications. The present invention provides an improved method of tracking receiver frequency offsets in a receiver for MIMO systems. These receiver based frequency offset components are caused by errors or inaccuracies in various receiver sub-systems such as phase lock loops or carrier frequency oscillator error, and sampling clock rate errors. The frequency offsets due to each of a number of receiver sub-systems are estimated by monitoring frequency offsets on a number of channels or subcarriers (such as OFDM pilot channels) on different frequencies. These channel frequency offsets are preferably estimated by detecting the phase rotation between adjacent pilot symbols on each respective channel. They are then weighted according to a quality parameter of the estimates, which corresponds to their accuracy. An example of a quality parameter is the effective SNR of the respective channels, or preferably the error variance of the phase rotation. In an embodiment the quality parameter is or is proportional to ∥Hx∥2. The weighted channel frequency offsets are then used to determine one or more receiver sub-system frequency offset components. For example a least squares line fit analysis can be performed.
摘要翻译： 本发明涉及估计和校正无线接收机中的频率偏移误差，并且特别地但并不排他地涉及MIMO WLAN应用。 本发明提供了一种在MIMO系统的接收机中跟踪接收机频率偏移的改进方法。 这些基于接收机的频率偏移分量由各种接收机子系统中的错误或不准确性引起，例如锁相环或载波频率振荡器错误以及采样时钟速率误差。 通过在不同频率上的多个信道或子载波（例如OFDM导频信道）上监视频率偏移来估计由多个接收机子系统中的每一个引起的频率偏移。 这些信道频率偏移优选地通过检测每个相应信道上的相邻导频符号之间的相位旋转来估计。 然后根据估计的质量参数对它们进行加权，这对应于它们的准确度。 质量参数的示例是相应通道的有效SNR，或优选地是相位旋转的误差方差。 在一个实施例中，质量参数为或等于∥Hx∥2。 加权的信道频率偏移然后用于确定一个或多个接收机子系统频率偏移分量。 例如，可以执行最小二乘线拟合分析。
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公开(公告)号：US20080075183A1
公开(公告)日：2008-03-27
申请号：US11848265
申请日：2007-08-31
IPC分类号： H04L27/28
CPC分类号： H04L25/067 , H04L25/03242
摘要： In a lattice-reduction-aided receiver based wireless communications system, soft estimates of transmitted bit values are determined from a received signal by applying lattice reduction to the channel estimate and equalising the received signal in accordance with the reduced basis channel, and determining probabilities of transmitted bits having particular values by generating a set of candidate vectors in the reduced basis based on nearest candidate vectors, determining a corresponding transmitted symbol vector for each candidate vector and, on the basis of the received signal determining the probability of each transmitted bit value having been transmitted.
摘要翻译： 在基于格子减少辅助的基于接收机的无线通信系统中，通过对信道估计应用网格约简并根据减少的基本信道对接收到的信号进行均衡，从接收信号确定发送比特值的软估计，并且确定 通过基于最近的候选向量在减少的基础中生成一组候选向量来确定具有特定值的发送比特，确定每个候选向量的对应的发送符号向量，并且基于确定每个发送的比特值具有的概率的接收信号 被传送
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公开(公告)号：US20050195734A1
公开(公告)日：2005-09-08
申请号：US11033865
申请日：2005-01-13
申请人： Magnus Sandell , Darren McNamara
发明人： Magnus Sandell , Darren McNamara
CPC分类号： H04B7/0684 , H04L5/0023 , H04L5/0048 , H04L25/0226 , H04L27/2613
摘要： The invention relates to apparatus, methods, processor control code and signals for channel estimation in MIMO (Multiple-input Multiple-output) OFDM (Orthogonal Frequency Division Multiplexed) communication systems. An OFDM signal is transmitted from an OFDM transmitter using a plurality of transmit antennas but has one or more nulled subcarriers, corresponding to windowing in the frequency domain. The OFDM signal is adapted for channel estimation for channels associated with said transmit antennas by the inclusion of orthogonal training sequence data in the signal from each said antenna. The training sequence data is derived from substantially orthogonal training sequences for each said transmit antenna, the training sequences being constructed based upon sequences of values Xmk=exp(−j2πkm/M) where k indexes a value in a said sequence, m indexes a transmit antenna, and M is the number of transmit antennas. Embodiments of these techniques provide training sequences that are more robust to, inter alia, nulled subcarriers.
摘要翻译： 本发明涉及用于MIMO（多输入多输出）OFDM（正交频分复用）通信系统中的信道估计的装置，方法，处理器控制代码和信号。 使用多个发送天线从OFDM发射机发送OFDM信号，但是具有与频域中的窗口对应的一个或多个无效副载波。 通过在每个所述天线的信号中包括正交训练序列数据，OFDM信号适用于与所述发射天线相关联的信道的信道估计。 训练序列数据是从每个所述发射天线的基本上正交的训练序列导出的，训练序列是根据值的序列构建的，该序列是在线性公式描述=“在线公式”end =“lead”→> X ＆lt;＆lt;＆gt;＆lt;＆lt;＆gt;＆lt;＆lt;＆gt; = exp（-j 2 pikm / M）<？in-line-formula description =“In-line Formulas”end =“tail”？> 对所述序列中的值进行索引，m对发射天线进行索引，M是发射天线的数量。 这些技术的实施例提供对于特别是零位副载波更加鲁棒的训练序列。
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公开(公告)号：US20080019262A1
公开(公告)日：2008-01-24
申请号：US11757057
申请日：2007-06-01
申请人： Andrew Lillie , Darren McNamara , Magnus Sandell
发明人： Andrew Lillie , Darren McNamara , Magnus Sandell
IPC分类号： H04J11/00
CPC分类号： H04L25/0246 , H04L27/2647
摘要： This invention relates to methods, apparatus, and processor control code for signal detection in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexed (MIMO-OFDM) communications systems. A method for determining outputs from a received signal in a lattice-reduction-aided receiver based multi-carrier wireless communications system having a plurality of sub-carriers divided into a plurality of sets of sub-carriers, the method comprising performing a detection method for each of said sets, the detection method comprising the step of applying lattice reduction to said set of sub-carriers thereby generating a reduced basis channel response.
摘要翻译： 本发明涉及用于多输入多输出正交频分复用（MIMO-OFDM）通信系统中的信号检测的方法，装置和处理器控制码。 一种用于在具有被划分成多组副载波的多个子载波的基于格子约简的辅助接收机的多载波无线通信系统中确定来自接收信号的输出的方法，所述方法包括执行检测方法 每个所述集合，所述检测方法包括对所述子载波集合应用网格约简的步骤，从而生成减少的基本信道响应。
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公开(公告)号：US20050089112A1
公开(公告)日：2005-04-28
申请号：US10935189
申请日：2004-09-08
CPC分类号： H04L1/005 , H04L1/0618 , H04L25/03171 , H04L2025/03375
摘要： This invention is generally concerned with methods, apparatus and processor control code for decoding a signal received over a MIMO (multiple input-multiple output) channel. A method of decoding a signal encoded as a string of symbols over space and time and/or frequency, transmitted over a MIMO (multiple-input multiple-output) channel, and received at a plurality of receive antennas, each transmitted symbol having one of a plurality of values, said decoding comprising determining a probability distribution for each symbol of the transmitted string of symbols; the method comprising: determining an initial estimate of said transmitted string of symbols from said received signal using an estimate of a response of said MIMO channel; and determining from said initial estimate a probability distribution for each symbol of the transmitted string of symbols, the probability distribution representing the likelihood of a symbol of the string having each of its possible values when other symbols of the transmitted string are treated as noise.
摘要翻译： 本发明通常涉及用于对通过MIMO（多输入多输出）信道接收的信号进行解码的方法，装置和处理器控制码。 一种通过空间和时间和/或频率编码为符号串的信号的方法，其通过MIMO（多输入多输出）信道发送并在多个接收天线处接收，每个发射符号具有 多个值，所述解码包括确定所发送的符号串的每个符号的概率分布; 所述方法包括：使用所述MIMO信道的响应的估计来从所述接收信号确定所述发送的符号串的初始估计; 并且从所述初始估计中确定所发送的符号串的每个符号的概率分布，所述概率分布表示当发送的字符串的其他符号被视为噪声时具有其每个可能值的字符串的符号的似然性。
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公开(公告)号：US06934270B2
公开(公告)日：2005-08-23
申请号：US09816041
申请日：2001-03-23
申请人： Cristian Demetrescu , Konstantinos Samaras , Louis Gwyn Samuel , Magnus Sandell , Jian Jun Wu , Ran-Hong Yan
发明人： Cristian Demetrescu , Konstantinos Samaras , Louis Gwyn Samuel , Magnus Sandell , Jian Jun Wu , Ran-Hong Yan
CPC分类号： H04L1/0079 , H04W84/04
摘要： In the GPRS, a method of decoding uplink status having reduced interleaving depth in a RLC/MAC block is proposed; for RT-EGPRS users, all of the uplink flag bits are provided in the first burst of the four bursts; and for EGPRS users, nine bits of the uplink status flags are provided in the first burst of the RLC/MAC block and the remaining bits in the next three bursts. On receiving the first nine bits, a mobile performs an autocorrelation to identify the USF whether it belongs to the EGPRS or to the RT-EGPRS group.
摘要翻译： 在GPRS中，提出了一种在RLC / MAC块中解码具有降低的交织深度的上行链路状态的方法; 对于RT-EGPRS用户，在四个突发的第一个突发中提供所有上行链路标志位; 对于EGPRS用户，在RLC / MAC块的第一突发中提供9比特的上行链路状态标志，并且在下一个三个突发中提供其余的比特。 在接收前9位时，移动台执行自相关以识别USF是属于EGPRS还是RT-EGPRS组。
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7.发明授权公开(公告)号：US07359466B2
公开(公告)日：2008-04-15
申请号：US09938453
申请日：2001-08-24
IPC分类号： H04B1/10
CPC分类号： H04L25/03012 , H04B1/707 , H04B7/0891 , H04L1/06 , H04L25/0242 , H04L25/03331 , H04L2025/03605 , H04L2025/03617
摘要： In a MIMO system the bit error rate floor caused by time dispersion is reduced by employing a joint minimum mean square error (MMSE) equalizer for all of the respective transmit antenna—receive antenna pairings that are possible in the MIMO system. The resulting joint equalization compensates not only for the impact of the channel on the transmit antenna—receive antenna pairings but also for the interference of the other transmit antennas on any given receive antenna. The joint equalization outperforms simply replicating the prior art minimum mean square error (MMSE) equalizer for each transmit antenna—receive antenna pairings.
摘要翻译： 在MIMO系统中，通过对MIMO系统中可能的所有相应的发射天线 - 接收天线配对采用联合最小均方误差（MMSE）均衡器来降低由时间色散引起的误比特率底层。 所产生的联合均衡不仅补偿了信道对发射天线 - 接收天线配对的影响，而且补偿了其他发射天线在任何给定的接收天线上的干扰。 联合均衡优于简单地复制现有技术的每个发射天线 - 接收天线配对的最小均方误差（MMSE）均衡器。
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公开(公告)号：US20080019428A1
公开(公告)日：2008-01-24
申请号：US11781695
申请日：2007-07-23
IPC分类号： H04B1/69
CPC分类号： H04L1/0631 , H04L1/005 , H04L1/0054 , H04L1/0625
摘要： Information is detected in a signal received from a transmission over a MIMO channel from a plurality of transmit antennas. The information is encoded as QAM symbols over space and time and/or frequency. A method of detection is provided, comprising arranging the available QAM symbols into a hierarchical tree structure, each level of the tree structure providing a greater level of granularity than the previous and, for each level of the tree structure from the least specific onwards, for each selected branch of the tree structure in said level, determining a branch likelihood measure, representing the approximated likelihood of a received signal containing a symbol in said branch, selecting one or more of said branches on the basis of their branch likelihood measures, said selected branches being selected for consideration in the next level of the tree structure, such that, at a last level, wherein each branch thereof corresponds to a symbol, said branch likelihood measure for a branch corresponds to a likelihood of said received signal containing the corresponding symbol. Corresponding detector apparatus is further provided.
摘要翻译： 在从多个发射天线通过MIMO信道的传输接收的信号中检测信息。 该信息在空间和时间和/或频率上被编码为QAM符号。 提供了一种检测方法，包括将可用的QAM符号布置到分层树结构中，树状结构的每个级别提供比先前的更高的粒度级别，并且对于来自最不特定的树结构的每个级别，为了 所述级别中的树结构的每个选择的分支，确定表示在所述分支中包含符号的接收信号的近似可能性的分支似然度量度，基于它们的分支似然度量来选择所述分支中的一个或多个，所述选择 分支被选择用于树结构的下一级中考虑，使得在最后一级，其中每个分支对应于符号，所述分支的分支似然度量对应于包含对应符号的所述接收信号的似然性 。 还提供了相应的检测器装置。
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公开(公告)号：US20060182206A1
公开(公告)日：2006-08-17
申请号：US11267495
申请日：2005-11-07
申请人： Justin Coon , Magnus Sandell
发明人： Justin Coon , Magnus Sandell
CPC分类号： H04B7/0684 , H04B7/0678
摘要： A method of estimating channel response in a communications system comprising a transmitting device having a plurality of transmit antennas and a receiving device having at least one receive antenna, the method comprising: (a) Superimposing training sequences onto transmit data to be transmitted by the transmit antennas in order to form a composite message, wherein the training sequences for each transmit antenna are arranged such that they are non-overlapping in the frequency domain; (b) Transmitting the composite message from step (a); (c) Receiving data at the receiving device and then performing the following steps across all channels i. Equalising received data to remove channel distortion; ii. detecting an estimate for the transmit data; iii. using the estimate of the transmit data from step (c)(ii) in order to derive an estimate of the received training sequences as modified by the channel response from the received data; iv. comparing the estimate of channel modified training sequences from step (c)(iii) with the original training sequences in order to estimate the channel response
摘要翻译： 一种在包括具有多个发射天线的发射设备和具有至少一个接收天线的接收设备的通信系统中估计信道响应的方法，所述方法包括：（a）将训练序列叠加到由所述传输 天线以形成复合消息，其中每个发射天线的训练序列被布置为使得它们在频域中不重叠; （b）从步骤（a）发送复合消息; （c）在接收设备接收数据，然后在所有信道上执行以下步骤。 均衡接收到的数据以消除信道失真; ii。 检测所述发送数据的估计; iii。 使用来自步骤（c）（ii）的发送数据的估计，以便从接收到的数据导出由信道响应修改的接收到的训练序列的估计; iv。 将来自步骤（c）（iii）的信道修改训练序列的估计与原始训练序列进行比较，以估计信道响应
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公开(公告)号：US20080292016A1
公开(公告)日：2008-11-27
申请号：US12187142
申请日：2008-08-06
IPC分类号： H04L27/28
CPC分类号： H04L1/005 , H04L1/0618 , H04L25/03171 , H04L2025/03375
摘要： This invention is generally concerned with methods, apparatus and processor control code for decoding a signal received over a MIMO (multiple input-multiple output) channel.A method of decoding a signal encoded as a string of symbols over space and time and/or frequency, transmitted over a MIMO (multiple-input multiple-output) channel, and received at a plurality of receive antennas, each transmitted symbol having one of a plurality of values, said decoding comprising determining a probability distribution for each symbol of the transmitted string of symbols; the method comprising: determining an initial estimate of said transmitted string of symbols from said received signal using an estimate of a response of said MIMO channel; and determining from said initial estimate a probability distribution for each symbol of the transmitted string of symbols, the probability distribution representing the likelihood of a symbol of the string having each of its possible values when other symbols of the transmitted string are treated as noise.
摘要翻译： 本发明通常涉及用于对通过MIMO（多输入多输出）信道接收的信号进行解码的方法，装置和处理器控制码。 一种通过空间和时间和/或频率编码为符号串的信号的方法，其通过MIMO（多输入多输出）信道发送并在多个接收天线处接收，每个发射符号具有 多个值，所述解码包括确定所发送的符号串的每个符号的概率分布; 所述方法包括：使用所述MIMO信道的响应的估计来从所述接收信号确定所述发送的符号串的初始估计; 并且从所述初始估计中确定所发送的符号串的每个符号的概率分布，所述概率分布表示当发送的字符串的其他符号被视为噪声时具有其每个可能值的字符串的符号的似然性。
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