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31. 发明授权

US07027503B2 Receiver with a decision feedback equalizer and a linear equalizer 有权
公开(公告)号：US07027503B2
公开(公告)日：2006-04-11
申请号：US10162976
申请日：2002-06-04
申请人： John Smee , Ivan Jesus Fernandez-Corbaton , Srikant Jayaraman
发明人： John Smee , Ivan Jesus Fernandez-Corbaton , Srikant Jayaraman
IPC分类号： H03H7/30 , H03H7/40 , H03K5/159
CPC分类号： H04L1/188 , H04L1/20 , H04L25/03038 , H04L25/03057 , H04L2025/03573 , H04L2025/03617
摘要： Techniques for selecting either a DFE or an LE for use to equalize a received signal, and for quickly and efficiently determining the coefficients for the selected equalizer. In an embodiment, a method is provided whereby the DFE is initially adapted based on the received signal and a particular adaptive algorithm (e.g., the LMS algorithm) for an initial time period. A quality metric is then determined for an output of the DFE. The DFE is selected for use if the quality metric is better than a threshold value, and the LE is selected otherwise. If the LE is selected, then the initial values for the coefficients of the LE may be derived based on the coefficients of a feed-forward filter and a feedback filter for the DFE, and the LE coefficients may further be adapted for an additional time period prior to its use to equalize the received signal.

32. 发明授权

US07012952B2 Method and apparatus for adjusting delay in systems with time-burst pilot and fractionally spaced equalizers 有权
$Method and apparatus for adjusting delay in systems with time-burst pilot and fractionally spaced equalizers$
公开(公告)号：US07012952B2
公开(公告)日：2006-03-14
申请号：US09921513
申请日：2001-08-01
申请人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee
发明人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee
IPC分类号： H04B1/707
CPC分类号： H04B1/7115 , H04B1/7117 , H04B1/712 , H04B2201/70707 , H04L2025/03375 , H04L2025/03509
摘要： A weighted mean arrival time determines a delay offset of a fractionally spaced equalizer. The weighted mean arrival time is determined using path arrival times and energies from a Rake receiver. The difference between a weighted mean arrival time and a current delay offset is set to a difference X, in units of the equalizer tap spacing. If the difference X is greater than or equal to 1 or less than or equal to −1, then the current delay offset is updated by an incremental delay offset and the equalizer filter coefficients are shifted by a number of tap spacings. Otherwise, the current delay offset is not updated and the filter coefficients of the fractionally spaced equalizer are not shifted. Adaptation of the filter coefficients and updates of the delay offset of the equalizer occur only during pilot bursts so as to minimize adaptation transients.

33. 发明授权

US06901243B2 Method and apparatus for mitigating adjacent channel interference in a wireless communication system 失效
标题翻译：用于减轻无线通信系统中的相邻信道干扰的方法和装置
公开(公告)号：US06901243B2
公开(公告)日：2005-05-31
申请号：US10007298
申请日：2001-11-08
申请人： Srikant Jayaraman , John E. Smee , Ivan Jesus Fernandez Corbaton
发明人： Srikant Jayaraman , John E. Smee , Ivan Jesus Fernandez Corbaton
IPC分类号： H04B1/707 , H04B1/00 , H04B1/10
CPC分类号： H04B1/1036
摘要： Techniques for detecting and mitigating adjacent channel interference (ACI) in a wireless (e.g., CDMA) communication system. In one aspect, ACI may be determined by signaling or detected by filtering a pre-processed signal in each frequency range where ACI may be present (e.g., with a respective bandpass filter), estimating the energy of the filtered signal for each frequency range, comparing the estimated energy against an ACI threshold, and indicating the presence or absence of ACI at each frequency range based on the result of the comparison. In another aspect, a selectable filter (e.g., a FIR filter) having a number of possible filter responses (e.g., provided by a number of sets of filter coefficients) may be used to provide filtering for the pre-processed signal and to reject any detected ACI. One of the possible filter responses is selected for use depending on whether and where ACI has been detected.
摘要翻译：用于在无线（例如CDMA）通信系统中检测和减轻相邻信道干扰（ACI）的技术。在一个方面，可以通过信令来确定ACI，或者通过对可能存在ACI的每个频率范围（例如，使用相应的带通滤波器）滤波预处理的信号来检测ACI，估计每个频率范围的滤波信号的能量，将估计的能量与ACI阈值进行比较，并且基于比较结果来指示每个频率范围内是否存在ACI。在另一方面，可以使用具有多个可能的滤波器响应（例如，由多个滤波器系数组提供）的可选滤波器（例如，FIR滤波器）来为预处理的信号提供滤波并且拒绝任何检测到ACI。选择一种可能的过滤器响应来使用，具体取决于是否检测到ACI。

34. 发明授权

US06745052B2 Method and apparatus for signal equalization in a communication system with multiple receiver antennas 失效
标题翻译：具有多个接收天线的通信系统中信号均衡的方法和装置
公开(公告)号：US06745052B2
公开(公告)日：2004-06-01
申请号：US09918770
申请日：2001-07-27
申请人： Ivan Jesus Fernandez Corbaton , John E. Smee , Srikant Jayaraman
发明人： Ivan Jesus Fernandez Corbaton , John E. Smee , Srikant Jayaraman
IPC分类号： H04M100
CPC分类号： H04B7/0854 , H04B7/0845 , H04L1/0618
摘要： A communication receiver (400) minimizes a combined local and global mean square error for signal equalization. A base station (101) or a mobile station (102-104) may include a plurality of antennas (292) for receiving a plurality of signals transmitted from a common source. The plurality of signals carry a common stream of data symbols. A pre-processing block (299) processes the received signals to produce a plurality of processed received signals (298). A signal equalizer (401) minimizes a combined local and global MSE over the processed received signals (298) to produce a combined signal (499). A decoder decodes the combined signal (499) to retrieve the stream of data symbols. A processor is configured for combining a local MSE and a global MSE in accordance with an adjustable weighting factor &agr; to produce the combined local and global MSE.
摘要翻译：通信接收机（400）使用于信号均衡的组合的局部和全局均方误差最小化。基站（101）或移动台（102-104）可以包括用于接收从公共源发送的多个信号的多个天线（292）。多个信号携带公共数据符号流。预处理块（299）处理所接收的信号以产生多个经处理的接收信号（298）。信号均衡器（401）使经过处理的接收信号（298）的组合本地和全局MSE最小化以产生组合信号（499）。解码器解码组合信号（499）以检索数据符号流。处理器被配置为根据可调加权因子α来组合本地MSE和全局MSE以产生组合的本地和全局MSE。

35. 发明授权

US07136428B2 Systems and techniques for measuring the performance of a communications system 有权
公开(公告)号：US07136428B2
公开(公告)日：2006-11-14
申请号：US09924342
申请日：2001-08-06
申请人： Ivan Jesus Fernandez Corbaton , John E. Smee , Srikant Jayaraman
发明人： Ivan Jesus Fernandez Corbaton , John E. Smee , Srikant Jayaraman
IPC分类号： H03K9/00
CPC分类号： H04L1/20 , H04B1/71055 , H04B1/7115 , H04L25/03038 , H04L2025/03477 , H04L2025/03617
摘要： Systems and techniques for measuring the performance of a communications channel is disclosed which includes receiving a signal from the communications channel, filtering the signal, estimating a bias introduced by the filtering of the signal, and computing a parameter of the communications channel as a function of the estimated bias. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

36. 发明授权

US07046726B2 Method and apparatus for hybrid decision feedback equalization 有权
标题翻译：混合判决反馈均衡的方法和装置
公开(公告)号：US07046726B2
公开(公告)日：2006-05-16
申请号：US10199159
申请日：2002-07-18
申请人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee
发明人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee
IPC分类号： H04L27/38
CPC分类号： H04L25/03267 , H04L25/03057 , H04L2025/03496
摘要： A method and apparatus for a decision feedback equalizer wherein a correction term is used to compensate for slicer errors, thus avoiding error propagation. Filter coefficients for the equalizer are selected so as to minimize a cost function for the equalizer. The cost function calculation includes a correction term. The correction term is a function of the energy of the filter coefficients. In one embodiment, the cost function includes a Mean Squared Error (MSE) calculation. The equalizer includes a coefficient generator responsive to the correction term. The correction term may depend on the Signal-to-Interference-and-Noise Ratio (SINR) at the output of the equalizer.
摘要翻译：一种用于判决反馈均衡器的方法和装置，其中校正项用于补偿限幅器误差，从而避免错误传播。选择用于均衡器的滤波器系数，以便使均衡器的成本函数最小化。成本函数计算包括校正项。校正项是滤波器系数的能量的函数。在一个实施例中，成本函数包括均方误差（MSE）计算。均衡器包括响应于校正项的系数发生器。校正项可以取决于均衡器的输出端的信号与干扰与噪声比（SINR）。

37. 发明授权

US06983125B2 Method and apparatus for varying the length of an adaptive equalizer based on doppler frequency 有权
公开(公告)号：US06983125B2
公开(公告)日：2006-01-03
申请号：US09965204
申请日：2001-09-25
申请人： John E. Smee , Ivan Jesus Fernandez-Corbaton , Srikant Jayaraman
发明人： John E. Smee , Ivan Jesus Fernandez-Corbaton , Srikant Jayaraman
IPC分类号： H04B1/00 , H03H7/30
CPC分类号： H04L25/03038 , H04L2025/03375 , H04L2025/03585
摘要： Systems and methods according to the present invention are described for adjusting the number of taps in an adaptive equalizer over time as the rate of change of a communications channel varies. The number of taps or “equalizer length” is adjusted based on an estimate of the Doppler frequency between the devices communicating over a channel. The Doppler frequency is reflective of the rate of change of the communications channel. Greater Doppler frequencies indicate a more quickly varying channel, and vice versa. It is therefore desirable to change the equalizer length (by adding or dropping taps) based on a measurement of the Doppler frequency. Equalizer length is increased as the Doppler frequency decreases. Conversely, equalizer length is decreased as the Doppler frequency increases. This enables the equalizer to achieve a better compromise between the competing goals of adaptation speed (less taps) and ISI reduction (more taps).

38. 发明授权

US06968001B2 Communication receiver with virtual parallel equalizers 有权
标题翻译：具有虚拟并行均衡器的通信接收器
公开(公告)号：US06968001B2
公开(公告)日：2005-11-22
申请号：US10226031
申请日：2002-08-21
申请人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee , Michael A. Howard
发明人： Srikant Jayaraman , Ivan Jesus Fernandez Corbaton , John E. Smee , Michael A. Howard
IPC分类号： H04L27/38 , H04B3/06 , H04B7/005 , H04L25/03 , H04L27/22 , H03H7/30 , H03H7/40 , H03K5/159
CPC分类号： H04L25/03038 , H04L2025/03566
摘要： Method for optimizing an equalizer at a receiver in a communication system by training virtual parallel equalizers. Multiple configurations are applied for training an equalizer, and a performance measurement or estimate determined. The performance measures of the multiple configurations are compared to determine the optimum configuration. The training and selection are performed at a rate sufficiently higher than the received sample rate as to allow optimization in between processing of data samples.
摘要翻译：用于通过训练虚拟并行均衡器在通信系统中的接收机处优化均衡器的方法。应用多种配置来训练均衡器，并确定性能测量或估计。比较多种配置的性能测量，以确定最佳配置。训练和选择以足够高于接收到的采样率的速率执行，以允许在数据样本的处理之间进行优化。

39. 发明授权

US07301990B2 Equalization of multiple signals received for soft handoff in wireless communication systems 有权
标题翻译：在无线通信系统中为软切换接收的多个信号的均衡
公开(公告)号：US07301990B2
公开(公告)日：2007-11-27
申请号：US10371795
申请日：2003-02-21
申请人： Srikant Jayaraman , John Smee , Ivan Jesus Fernandez-Corbaton
发明人： Srikant Jayaraman , John Smee , Ivan Jesus Fernandez-Corbaton
IPC分类号： H04B1/00
CPC分类号： H04L25/03038 , H04B7/022 , H04L25/0244 , H04L25/0256 , H04L2025/03375 , H04L2025/03426 , H04L2025/03477 , H04L2025/03605 , H04W24/00 , H04W36/08 , H04W36/18
摘要： Techniques for performing equalization of multiple signals received by a terminal in soft handoff with multiple base stations. The received signal at the terminal is conditioned and digitized to provide a stream of received samples, which is then equalized/filtered with multiple sets of coefficients to provide multiple streams of transmit chip estimates. One set of coefficients is provided for each base station and is used to provide a corresponding stream of transmit chip estimates. The multiple streams of transmit chip estimates are further processed to provide multiple streams of data symbol estimates, one stream of data symbol estimates for each base station. The multiple streams of data symbol estimates are then scaled with multiple scaling factors and combined to provide a stream of combined data symbol estimates. The processing for the multiple base stations may be performed by a single hardware unit in a time division multiplexed manner.
摘要翻译：用于在与多个基站的软切换中执行终端接收的多个信号的均衡的技术。在终端处接收的信号被调节并数字化以提供接收样本流，然后将其与多组系数进行均衡/滤波，以提供多个传输芯片估计流。为每个基站提供一组系数，并用于提供相应的传输芯片估计流。进一步处理多个发送码片估计流，以提供多个数据符号估计流，每个基站的数据符号估计数据流。然后用多个缩放因子对多个数据符号估计流进行缩放，并组合以提供组合的数据符号估计流。多个基站的处理可以由时分多路复用的单个硬件单元执行。

40. 发明申请

US20070086513A1 SYSTEM AND METHOD FOR ADJUSTING COMBINER WEIGHTS USING AN ADAPTIVE ALGORITHM IN WIRELESS COMMUNICATIONS SYSTEM 有权
标题翻译：使用无线通信系统中的自适应算法调整组合权重的系统和方法
公开(公告)号：US20070086513A1
公开(公告)日：2007-04-19
申请号：US11564824
申请日：2006-11-29
申请人： Ivan Fernandez-Corbaton , John Smee , Srikant Jayaraman
发明人： Ivan Fernandez-Corbaton , John Smee , Srikant Jayaraman
IPC分类号： H04B1/00
CPC分类号： H04B1/712 , H04B7/0854 , H04B7/0897 , H04B2201/70701
摘要： Method and apparatus to compute the combiner coefficients for wireless communication systems using an adaptive algorithm. One embodiment trains the weights on a signal known a priori that is time multiplexed with other signals, such as a pilot signal in a High Data Rate, HDR, system, wherein the signal is transmitted at full power. The adaptive algorithm recursively computes the weights during the pilot interval and applies the weights generated to the traffic signals. In one embodiment, the algorithm is a recursive least squares algorithm employing a transversal filter and weight calculation unit.
摘要翻译：使用自适应算法计算无线通信系统的组合器系数的方法和装置。一个实施例对先前已知的与其他信号进行时间复用的信号（例如高数据速率，HDR，系统中的导频信号）来训练权重，其中信号以全功率发送。自适应算法递归地计算导频间隔期间的权重，并将生成的权重应用于业务信号。在一个实施例中，算法是采用横向滤波器和权重计算单元的递归最小二乘法算法。

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