公开(公告)号：US08363697B2

公开(公告)日：2013-01-29

申请号：US11041136

申请日：2005-01-20

申请人： Matthew S. Grob ,  Peter J. Black ,  Srikant Jayaraman ,  Paul E. Jacobs

发明人： Matthew S. Grob ,  Peter J. Black ,  Srikant Jayaraman ,  Paul E. Jacobs

IPC分类号： H04B1/707 ,  H04B7/216 ,  H04B15/00 ,  H04H20/71

CPC分类号： H04L5/026 ,  H04L27/2607

摘要： Synchronized broadcast transmits a same broadcast content using a same waveform from multiple transmitters. Transmitters each apply a same spreading code for broadcast transmissions. In a spread-spectrum communication system having a time division multiplexed forward link, a synchronized broadcast transmission is inserted into a broadcast slot. One embodiment employs an Orthogonal Frequency Divisional Multiplex (OFDM) waveform for the synchronized broadcast. An OFDM receiver is then used to process the received synchronized broadcast transmission. An alternate embodiment implements a broadcast Pseudo-random Noise (PN) code for use by multiple transmitters. An equalizer is then employed to estimate the synchronized broadcast transmission.

公开(公告)号：US08126072B2

公开(公告)日：2012-02-28

申请号：US12491056

申请日：2009-06-24

申请人： June Namgoong ,  Hao Xu ,  Peter J. Black ,  Srikant Jayaraman

发明人： June Namgoong ,  Hao Xu ,  Peter J. Black ,  Srikant Jayaraman

IPC分类号： H04L27/28

CPC分类号： H04L1/20 ,  H04B1/1027 ,  H04L27/2647

摘要： The present patent application comprises a method and means for demodulating symbols, comprising converting an OFDM symbol from a time domain to a frequency domain, selecting pilot tones, making a soft decision based on received data, and estimating a channel frequency response. In another example, the method and means further comprises selecting guard tones. In another example, the method and means further comprises generating channel estimates for in-band and band-edge pilot tones.

摘要翻译： 本专利申请包括用于解调符号的方法和装置，包括将OFDM符号从时域转换到频域，选择导频音，基于接收到的数据进行软判决，以及估计信道频率响应。 在另一示例中，该方法和装置还包括选择保护音。 在另一示例中，该方法和装置还包括生成带内和带边导频音调的信道估计。

公开(公告)号：US07564775B2

公开(公告)日：2009-07-21

申请号：US11119240

申请日：2005-04-29

申请人： Srikant Jayaraman ,  Hao Xu ,  June Namgoong ,  Michael John Mangan ,  Peter J. Black

发明人： Srikant Jayaraman ,  Hao Xu ,  June Namgoong ,  Michael John Mangan ,  Peter J. Black

IPC分类号： H04J11/00

CPC分类号： H04L27/2662 ,  H04L1/20 ,  H04L5/0048 ,  H04L27/2695 ,  H04L2001/0093

摘要： A spread-spectrum communication system provides an effective signal-to-noise ratio (SNR) of received orthogonal frequency division multiplex (OFDM) slots in the presence of timing errors. Effective SNR can serve as a diagnostic tool for determining whether there was a timing error when a measured packet error rate (PER) remains high, and a predicted PER from the effective SNR remains low. A loop can use the effective SNR to control a time reference used by an OFDM decoder.

摘要翻译： 在存在定时误差的情况下，扩频通信系统提供接收到的正交频分复用（OFDM）时隙的有效信噪比（SNR）。 当测量的分组错误率（PER）保持为高时，有效SNR可以用作确定是否存在定时误差的诊断工具，并且来自有效SNR的预测的PER保持为低。 循环可以使用有效SNR来控制OFDM解码器使用的时间参考。

公开(公告)号：US20080101506A1

公开(公告)日：2008-05-01

申请号：US11933376

申请日：2007-10-31

申请人： Srikant Jayaraman ,  June Namgoong

发明人： Srikant Jayaraman ,  June Namgoong

IPC分类号： H03D1/00 ,  H04L27/06

CPC分类号： H04L25/025 ,  H03M13/413 ,  H03M13/6337 ,  H04L1/005 ,  H04L1/0054 ,  H04L1/0059 ,  H04L25/0228 ,  H04L25/0238 ,  H04L27/233 ,  H04L2027/003

摘要： A receiver for the GEO satellite reverse link, which uses the tail-biting convolutional code for error control, and methods to solve the problem of channel estimation is described. The channel estimate is initialized at each state using the pilot channel. Branch metric computation is used for circular decoding of the tail-biting convolutional code. The technique is effective when partial tail-biting is implemented.

摘要翻译： 描述了用于GEO卫星反向链路的接收机，其使用尾巴卷积码进行错误控制，并且描述了解决信道估计问题的方法。 使用导频信道在每个状态下初始化信道估计。 分支度量计算用于尾部卷积码的循环解码。 当实施部分尾巴时，该技术是有效的。

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.

公开(公告)号：US20060062322A1

公开(公告)日：2006-03-23

申请号：US11047347

申请日：2005-01-28

申请人： June Namgoong ,  Hao Xu ,  Peter Black ,  Srikant Jayaraman

发明人： June Namgoong ,  Hao Xu ,  Peter Black ,  Srikant Jayaraman

IPC分类号： H04B15/00 ,  H04K1/10 ,  H04L27/28

CPC分类号： H04L1/20 ,  H04B1/1027 ,  H04L27/2647

摘要： Noise variance estimation in wireless communications. Noise variance estimation includes receiving a signal including an OFDM symbol having, in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones, and estimating an effective noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones.

摘要翻译： 无线通信中的噪声方差估计。 噪声方差估计包括接收包括具有包括带内导频音频的带内音调和包括带边导频音和保护音的带边音调的OFDM符号的信号，估计带内音调的有效噪声方差 使用带内导频音调和频带内导频音调的估计，以及使用带边导频音估计带边音调的有效噪声方差，对带边导频音进行信道估计，以及 守卫色调。

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.

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。

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。

公开(公告)号：US08699465B2

公开(公告)日：2014-04-15

申请号：US12627974

申请日：2009-11-30

申请人： Bin Tian ,  Ahmad Jalali ,  Srikant Jayaraman ,  June Namgoong

发明人： Bin Tian ,  Ahmad Jalali ,  Srikant Jayaraman ,  June Namgoong

IPC分类号： H04W36/30 ,  H04W84/08 ,  H04W74/04

CPC分类号： H04B7/18543 ,  H04L1/0002 ,  H04L1/0026 ,  H04L1/0028 ,  H04L1/08 ,  Y02D50/10

摘要： In a synchronous application to control forward link (FL) data rates in a satellite system, user equipment (UE) repeatedly transmits a quality control measurement (QCM) index during a QCM period. During this QCM period, the data rate cannot change. The associated satellite transmits at a new rate corresponding to the QCM index. The UE knows that it will begin receiving new data at the new rate after a QCM delay. In an asynchronous application, a satellite transmits a rate change signal over a FL rate indication channel (RICH). A UE monitors the FL RICH for this signal. When the signal quality is to be low, the satellite sends only a single bit of the QCM index over a first orthogonal channel. When the signal quality is not low, the satellite transmits each bit of the QCM index in a separate orthogonal channel of the FL RICH.

摘要翻译： 在用于在卫星系统中控制前向链路（FL）数据速率的同步应用中，用户设备（UE）在QCM周期期间重复发送质量控制测量（QCM）索引。 在这个QCM期间，数据速率不能改变。 相关联的卫星以对应于QCM指数的新速率发射。 UE知道在QCM延迟之后，它将以新的速率开始接收新的数据。 在异步应用中，卫星通过FL速率指示信道（RICH）发送速率改变信号。 UE监视该信号的FL RICH。 当信号质量低时，卫星在第一个正交信道上只发送一个QCM索引的比特。 当信号质量不低时，卫星在FL RICH的单独的正交信道中发送QCM索引的每个比特。