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    • 3. 发明申请
    • DECODER FOR WIRELESS COMMUNICATION SYSTEM
    • 无线通信系统解码器
    • US20080019428A1
    • 2008-01-24
    • US11781695
    • 2007-07-23
    • Yugang JiaMagnus SandellChristophe AndrieuRobert Piechocki
    • Yugang JiaMagnus SandellChristophe AndrieuRobert Piechocki
    • H04B1/69
    • H04L1/0631H04L1/005H04L1/0054H04L1/0625
    • 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.
    • 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。
    • 4. 发明申请
    • Communications system, method and device
    • 通信系统,方法和设备
    • US20060182206A1
    • 2006-08-17
    • US11267495
    • 2005-11-07
    • Justin CoonMagnus Sandell
    • Justin CoonMagnus Sandell
    • H03D1/04H04B7/02
    • H04B7/0684H04B7/0678
    • 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
    • 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
    • 5. 发明申请
    • SIGNAL DECODING METHODS AND APPARATUS
    • 信号解码方法和设备
    • US20080292016A1
    • 2008-11-27
    • US12187142
    • 2008-08-06
    • Robert Jan PiechockiMagnus SandellSteve Carl Jamieson ParkerChristophe Andrieu
    • Robert Jan PiechockiMagnus SandellSteve Carl Jamieson ParkerChristophe Andrieu
    • H04L27/28
    • H04L1/005H04L1/0618H04L25/03171H04L2025/03375
    • 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.
    • 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。
    • 7. 发明申请
    • Transmission signals, methods and apparatus
    • 传输信号,方法和装置
    • US20050195734A1
    • 2005-09-08
    • US11033865
    • 2005-01-13
    • Magnus SandellDarren McNamara
    • Magnus SandellDarren McNamara
    • H04J99/00H04L27/26H04J11/00
    • H04B7/0684H04L5/0023H04L5/0048H04L25/0226H04L27/2613
    • 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.
    • 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。
    • 9. 发明申请
    • Frequency offset tracking
    • 频率偏移跟踪
    • US20060209979A1
    • 2006-09-21
    • US11261513
    • 2005-10-31
    • Magnus SandellDarren McNamaraSteve Parker
    • Magnus SandellDarren McNamaraSteve Parker
    • H04L1/02
    • H04L27/2657H04L27/2675H04L2027/0032H04L2027/0065H04L2027/0075
    • 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.
    • 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。