公开(公告)号：US07675962B2

公开(公告)日：2010-03-09

申请号：US11399886

申请日：2006-04-07

Applicant: Gokhan Mergen ,  Vignesh Suthuraman ,  Nitin Kasturi ,  Parvathanathan Subrahmanya

Inventor： Gokhan Mergen ,  Vignesh Suthuraman ,  Nitin Kasturi ,  Parvathanathan Subrahmanya

IPC: H04B1/00

CPC classification number: H04L25/0216 ,  H04L25/0218

Abstract: Techniques for deriving a channel impulse response estimate (CIRE) having improved quality are described. A first CIRE with multiple channel taps is obtained based on (1) an initial CIRE derived from a received pilot or (2) a filtered CIRE derived from the initial CIRE. In one aspect, the channel taps in the first CIRE are scaled with multiple scaling factors to obtain a second CIRE. For point-wise LMMSE scaling, the energy of each channel tap is estimated. The noise energy for the channel taps is also estimated, e.g., based on energies of channel taps on one or both edges of the first CIRE. Each channel tap is scaled based on a scaling factor determined by the energy of that channel tap and the noise energy. Each channel tap with energy below a threshold may be set to zero. In another aspect, the second CIRE is obtained by zeroing out selected ones of the channel taps in the first CIRE.

Abstract translation: 描述了用于导出具有改进的质量的信道脉冲响应估计（CIRE）的技术。 基于（1）从接收到的导频导出的初始CIRE或（2）从初始CIRE导出的滤波CIRE，获得具有多信道抽头的第一CIRE。 在一个方面，第一CIRE中的信道抽头被多个缩放因子缩放以获得第二CIRE。 对于逐点LMMSE缩放，估计每个通道抽头的能量。 也可以例如基于第一CIRE的一个或两个边缘上的信道抽头的能量来估计信道抽头的噪声能量。 每个通道抽头基于由该通道抽头的能量和噪声能量确定的缩放因子进行缩放。 能量低于阈值的每个通道抽头可以设置为零。 在另一方面，第二CIRE是通过对第一CIRE中的选通的信道抽头进行归零而获得的。

公开(公告)号：US20090041162A1

公开(公告)日：2009-02-12

申请号：US11836941

申请日：2007-08-10

Applicant: Yan Li ,  Parvathanathan Subrahmanya ,  Naveed Zaman

Inventor： Yan Li ,  Parvathanathan Subrahmanya ,  Naveed Zaman

IPC: H04L27/06

CPC classification number: H04B1/7083 ,  H04B1/70735 ,  H04B1/709

Abstract: A circuit and algorithm are disclosed for a step2 search of a three step search of synchronization channels in a W-CDMA system. A mobile terminal of the CDMA system includes an RF downconverter for receiving I and Q signals. A searcher, responsive to the I and Q signals, includes a first correlator for correlating the I and Q signals with a primary synchronization code on a primary synchronization channel, and a second correlator for correlating I and Q signals with a secondary synchronization code on a secondary synchronization channel. The correlated I and Q signals are added for each of the secondary synchronization codes. An energy calculator and a maximum energy detector use the correlated I and Q signals of both the primary and secondary synchronization channels to detect the most likely scrambling code group of secondary synchronization codes.

Abstract translation: 公开了一种针对W-CDMA系统中的同步信道的三步搜索的步骤2搜索的电路和算法。 CDMA系统的移动终端包括用于接收I和Q信号的RF下变频器。 响应于I和Q信号的搜索器包括用于将I信号与Q信号与主同步信道上的主同步码进行相关的第一相关器，以及用于使I和Q信号与第一同步码相关的第二相关器， 辅同步通道。 为每个辅助同步码添加相关的I和Q信号。 能量计算器和最大能量检测器使用主和次同步信道的相关I和Q信号来检测次同步码的最可能的扰码组。

公开(公告)号：US07363010B2

公开(公告)日：2008-04-22

申请号：US10827143

申请日：2004-04-15

Applicant: Hyukjun Oh ,  Parvathanathan Subrahmanya ,  Nitin Kasturi

Inventor： Hyukjun Oh ,  Parvathanathan Subrahmanya ,  Nitin Kasturi

IPC: H04B17/00

CPC classification number: H04W52/12 ,  H04W52/28

Abstract: Techniques for controlling transmit power for a data transmission sent on multiple data channels, which may be intermittently active, are described. Each data channel is monitored for activity (e.g., based on an error correction code, received signaling information, received block energy, and so on) and deemed to be dormant or not dormant (e.g., based on the amount of elapsed time since activity was last detected on the data channel). A signal quality (SIR) target may be maintained for each non-dormant data channel and updated based on the status of received data blocks for the data channel. A final SIR target, used for power control of the data transmission, may be set to the highest SIR target among the SIR targets for the non-dormant data channels. The final SIR target may also be updated directly based on the status of received data blocks for the non-dormant data channels.

Abstract translation: 描述了用于控制在可能间歇地活动的多个数据信道上发送的数据传输的发送功率的技术。 监视每个数据信道的活动（例如，基于纠错码，接收的信令信息，接收到的块能量等等），并被认为是休眠或不休眠（例如，基于从活动以来的经过时间量 最后在数据通道上检测到）。 可以为每个非休眠数据信道维持信号质量（SIR）目标，并且基于数据信道的接收数据块的状态来更新。 可以将用于数据传输的功率控制的最终SIR目标设置为非休眠数据信道的SIR目标中的最高SIR目标。 也可以基于非休眠数据信道的接收数据块的状态来直接更新最终SIR目标。

公开(公告)号：US20070127557A1

公开(公告)日：2007-06-07

申请号：US11502178

申请日：2006-08-09

Applicant: Parvathanathan Subrahmanya ,  Inyup Kang ,  Jia Fei ,  Rajesh Sundaresan

Inventor： Parvathanathan Subrahmanya ,  Inyup Kang ,  Jia Fei ,  Rajesh Sundaresan

IPC: H04B1/00 ,  H03H7/30

CPC classification number: H04B1/71057 ,  H04B7/0669 ,  H04B7/0673 ,  H04B7/0845 ,  H04L25/03044 ,  H04L25/03292 ,  H04L2025/03509

Abstract: This disclosure describes equalization techniques for spread spectrum wireless communication. The techniques may involve estimating a channel impulse response, estimating channel variance, and selecting filter coefficients for an equalizer based on the estimated channel impulse response and the estimated channel variance. Moreover, in accordance with this disclosure, the channel variance estimation involves estimation of two or more co-variances for different received samples. Importantly, the equalizer is “fractionally spaced,” which means that the equalizer defines fractional filtering coefficients (filter taps), unlike conventional equalizers that presume that filter coefficients are defined at integer chip spacing. The techniques can allow the equalizer to account for antenna diversity, such as receive diversity, transmit diversity, or possibly both.

Abstract translation: 本公开描述了用于扩频无线通信的均衡技术。 这些技术可以包括基于所估计的信道脉冲响应和所估计的信道方差估计信道脉冲响应，估计信道方差，以及为均衡器选择滤波器系数。 此外，根据本公开，信道方差估计涉及对于不同接收样本的两个或多个协方差的估计。 重要的是，均衡器是“分数间隔”的，这意味着均衡器定义了分数滤波系数（滤波器抽头），不同于传统的均衡器，假设滤波器系数是以整数芯片间隔定义的。 这些技术可以允许均衡器考虑天线分集，例如接收分集，发射分集，或者可能两者。

公开(公告)号：US20060174179A1

公开(公告)日：2006-08-03

申请号：US11049991

申请日：2005-02-02

Applicant: Arun Visvanathan ,  Amit Butala ,  Parvathanathan Subrahmanya

Inventor： Arun Visvanathan ,  Amit Butala ,  Parvathanathan Subrahmanya

IPC: H03M13/00

CPC classification number: H04W52/12 ,  H04B1/7172 ,  H04L1/20 ,  H04L1/201 ,  H04L1/208 ,  H04W52/18 ,  H04W52/20 ,  H04W52/24 ,  H04W52/44

Abstract: To perform erasure detection for an intermittently active transport channel with unknown format, a receiver determines an energy metric and a symbol error rate (SER) for a received block with CRC failure. The receiver computes uncorrelated random variables u and v for the received block based on the energy metric and SER, the estimated means and standard deviations of the energy metric and SER, and a correlation coefficient indicative of the correlation between the energy metric and SER. The receiver then evaluates the uncorrelated random variables u and v based on at least one decision criterion and declares the received block to be an erased block or a DTX block based on the result of the evaluation. The decision criterion may be defined based on a target probability of false alarm and adjusted based on another metric, such as a zero state bit, for the received block.

Abstract translation: 为了对具有未知格式的间歇活动传输信道执行擦除检测，接收机确定具有CRC故障的接收块的能量度量和符号错误率（SER）。 接收机基于能量度量和SER，能量度量和SER的估计平均值和标准偏差以及表示能量度量与SER之间的相关性的相关系数，计算接收块的不相关随机变量u和v。 然后，接收机基于至少一个决策标准来评估不相关的随机变量u和v，并且基于评估结果将接收到的块声明为擦除块或DTX块。 可以基于目标误报率概率来定义判定标准，并且基于接收块的另一个度量（例如零状态位）进行调整。

公开(公告)号：US20050079846A1

公开(公告)日：2005-04-14

申请号：US10684771

申请日：2003-10-14

Applicant: Andrew Sendonaris ,  Da-shan Shiu ,  Dominic Farmer ,  Jeremy Lin ,  Parvathanathan Subrahmanya ,  Thomas Rowland

Inventor： Andrew Sendonaris ,  Da-shan Shiu ,  Dominic Farmer ,  Jeremy Lin ,  Parvathanathan Subrahmanya ,  Thomas Rowland

IPC: G01S19/25 ,  G01S19/23 ,  H04B1/38 ,  H04L27/00 ,  H04B1/06 ,  H04L7/04

CPC classification number: H04L27/0014 ,  G01S19/235 ,  H04B1/3805 ,  H04L2027/0077

Abstract: Systems and techniques are disclosed relating to wireless communications. These systems and techniques involve wireless communications wherein a device may be configured to recover an information signal from a carrier using a reference signal, detect a frequency error in the information signal; and periodically tune the reference signal to reduce the frequency error.

Abstract translation: 公开了与无线通信有关的系统和技术。 这些系统和技术涉及无线通信，其中设备可以被配置为使用参考信号从载波恢复信息信号，检测信息信号中的频率误差; 并定期调谐参考信号以减少频率误差。

公开(公告)号：US06775242B2

公开(公告)日：2004-08-10

申请号：US09901831

申请日：2001-07-09

Applicant: Francesco Grilli ,  Charles E. Wheatley, III ,  Serge Willenegger ,  Parvathanathan Subrahmanya

Inventor： Francesco Grilli ,  Charles E. Wheatley, III ,  Serge Willenegger ,  Parvathanathan Subrahmanya

IPC: G01R3108

CPC classification number: H04W56/002 ,  H04B7/2668 ,  H04B2201/70702 ,  H04W56/001 ,  H04W56/0015 ,  H04W56/0045 ,  H04W92/20

Abstract: Schemes to time-align transmissions from multiple base stations to a terminal. To achieve time-alignment, differences between the arrival times of transmissions from the base stations, as observed at the terminal, are determined and provided to the system and used to adjust the timing at the base stations such that terminal-specific radio frames arrive at the terminal within a particular time window. In one scheme, a time difference between two base stations is partitioned into a frame-level time difference and a chip-level time difference. Whenever requested to perform and report time difference measurements, the terminal measures the chip-level timing for each candidate base station relative to a reference base station. Additionally, the terminal also measures the frame-level timing and includes this information in the time difference measurement only if required. Otherwise, the terminal sets the frame-level part to a predetermined value (e.g., zero).

Abstract translation: 将来自多个基站的传输时间对齐到终端的方案。 为了实现时间对准，确定在终端观察到的来自基站的传输的到达时间之间的差异，并将其提供给系统，并用于调整基站处的定时，使得终端专用无线帧到达 终端在特定的时间窗口内。 在一个方案中，两个基站之间的时差被划分为帧级时间差和码片级时间差。 无论何时请求执行和报告时差测量，终端测量每个候选基站相对于参考基站的芯片级定时。 此外，终端还测量帧级定时，并且仅在需要时在时差测量中包括该信息。 否则，终端将帧级部分设置为预定值（例如，零）。

公开(公告)号：US06760573B2

公开(公告)日：2004-07-06

申请号：US10261976

申请日：2002-10-01

Applicant: Parvathanathan Subrahmanya ,  Jeremy H. Lin

Inventor： Parvathanathan Subrahmanya ,  Jeremy H. Lin

IPC: H04B118

CPC classification number: H04B1/712

Abstract: Techniques for inner/outer loop tracking that is stable and provides desirable loop convergence characteristics are disclosed. In one aspect, the contribution from any one inner loop to the tracking function of the outer loop is limited, to prohibit any one received signal component from dominating the outer loop. In another aspect, the rate of outer loop tracking variation is controlled to provide inner and outer loop stability. Various other aspects are also presented. These aspects have the benefit of providing stable inner and outer loop control, as well as efficient convergence and tracking by the various loops, resulting in reduced frequency error and improved communication performance.

公开(公告)号：US08576965B2

公开(公告)日：2013-11-05

申请号：US12831462

申请日：2010-07-07

Applicant: Madihally J. Narasimha ,  Je Woo Kim ,  Nitin Kasturi ,  Parvathanathan Subrahmanya

Inventor： Madihally J. Narasimha ,  Je Woo Kim ,  Nitin Kasturi ,  Parvathanathan Subrahmanya

IPC: H04B1/10

CPC classification number: H04B1/525 ,  G01S19/21 ,  H04B1/3805 ,  H04B1/406

Abstract: Certain embodiments of the present disclosure support techniques for interference cancellation in a multi-mode wireless modem that supports coexistence of different radio technologies.

Abstract translation: 本公开的某些实施例支持支持不同无线电技术共存的多模式无线调制解调器中的干扰消除技术。

公开(公告)号：US08554151B2

公开(公告)日：2013-10-08

申请号：US12960283

申请日：2010-12-03

Applicant: Young Geun Cho ,  Aditya Dua ,  Feng Lu ,  Gokhan Mergen ,  Subramanya P. N. Rao ,  Abhinav Gupta ,  Parvathanathan Subrahmanya

Inventor： Young Geun Cho ,  Aditya Dua ,  Feng Lu ,  Gokhan Mergen ,  Subramanya P. N. Rao ,  Abhinav Gupta ,  Parvathanathan Subrahmanya

IPC: H04B17/00

CPC classification number: H04L1/20

Abstract: Methods and apparatuses for data aided channel quality estimation using both pilot and data information are disclosed herein. In one exemplary aspect, a method for estimating channel quality in a wireless communication system is disclosed. The method comprises estimating a pilot noise variance based on a pilot signal received from a base station on a downlink and estimating a data noise variance based on a data signal received from the base station on the downlink. The method also comprises combining the pilot noise variance and the data noise variance to obtain a combined noise variance, and estimating the channel quality based on the combined noise variance.

Abstract translation: 本文公开了使用导频和数据信息的数据辅助信道质量估计的方法和装置。 在一个示例性方面，公开了一种用于估计无线通信系统中的信道质量的方法。 该方法包括基于从下行链路上的基站接收的导频信号来估计导频噪声方差，并且基于在下行链路上从基站接收的数据信号来估计数据噪声方差。 该方法还包括组合导频噪声方差和数据噪声方差以获得组合噪声方差，并且基于组合的噪声方差来估计信道质量。