公开(公告)号：US08665693B1

公开(公告)日：2014-03-04

申请号：US13212572

申请日：2011-08-18

申请人： Shi Cheng ,  Ravi Narasimhan

发明人： Shi Cheng ,  Ravi Narasimhan

IPC分类号： H04J9/00

CPC分类号： H04L1/005 ,  H04B7/0413 ,  H04L1/0048 ,  H04L25/0204 ,  H04L25/022 ,  H04L25/0228 ,  H04L25/03891

摘要： A system and method are provided for Soft Interference Cancellation (SIC) in receiving Single Carrier Frequency Division Multiple Access (SC-FDMA) Multiple-Input Multiple Output (MIMO) signals. A receiver with Mr antennas accepts multicarrier signals transmitted simultaneously, with N overlapping carrier frequencies. The receiver removes a cyclic prefix (CP), and fast Fourier transforms (FFT) the multicarrier signal from each antenna, supplying Mr number of N-tone signals y. Using either parallel SIC (P-SIC) or successive SIC (S-SIC), interference is canceled in each of the Mr signals, and soft symbols are supplied for each of U layers. Interference is canceled using the P-SIC process by parallel processing the U layers in an i-th iteration, in response to feedback from an (i−1)th iteration. Alternatively, interference is canceled using the S-SIC process by sequentially processing the U layers in an i-th iteration, in the order of u0,u1, . . . , uU−1, using feedback generated from previously processed layers.

摘要翻译： 在接收单载波频分多址（SC-FDMA）多输入多输出（MIMO）信号的情况下，提供了用于软干扰消除（SIC）的系统和方法。 具有Mr天线的接收机接收同时传输的多载波信号，具有N个重叠载波频率。 接收器从每个天线去除循环前缀（CP）和快速傅里叶变换（FFT）多载波信号，提供Mr个N音信号y。 使用并行SIC（P-SIC）或连续SIC（S-SIC），在每个Mr信号中消除干扰，并为每个U层提供软符号。 响应于来自第（i-1）次迭代的反馈，使用P-SIC处理通过在第i次迭代中并行处理U层来消除干扰。 或者，通过在第i次迭代中以u0，u1，...的顺序依次处理U层，使用S-SIC处理来消除干扰。 。 。 ，uU-1，使用从先前处理的层生成的反馈。

公开(公告)号：US08300743B1

公开(公告)日：2012-10-30

申请号：US12393547

申请日：2009-02-26

申请人： Ravi Narasimhan

发明人： Ravi Narasimhan

IPC分类号： H03D1/04

CPC分类号： H04L27/266 ,  H04L25/0228 ,  H04L27/2659 ,  H04L27/2662 ,  H04L27/2675 ,  H04L27/2695

摘要： A method for updating channel estimates in an orthogonal frequency division multiplexing receiver of a wireless local area network includes generating channel estimates for an orthogonal frequency division multiplexing subcarrier as a function of subcarrier index values. The method includes generating a complex number by summing a product of frequency domain signals and the channel estimates for each of the subcarrier index values and dividing the sum by a sum of a squared absolute value of the channel estimate for each of the subcarrier index values. The method includes multiplying the complex number by the channel estimates to generate updated channel estimates.

摘要翻译： 一种用于在无线局域网的正交频分复用接收机中更新信道估计的方法包括：生成正交频分复用子载波的信道估计，作为子载波索引值的函数。 该方法包括通过对频域信号的乘积和每个子载波索引值的信道估计相加来产生复数，并将和除以每个子载波索引值的信道估计的平方绝对值之和。 该方法包括将复数乘以信道估计以产生更新的信道估计。

公开(公告)号：US08238496B1

公开(公告)日：2012-08-07

申请号：US12782066

申请日：2010-05-18

申请人： Ravi Narasimhan ,  Shi Cheng

发明人： Ravi Narasimhan ,  Shi Cheng

IPC分类号： H03D1/04 ,  H03D1/06 ,  H03K5/01 ,  H03K6/04 ,  H04B1/10 ,  H04L1/00 ,  H04L25/08

CPC分类号： H04L25/0208 ,  H04L25/022 ,  H04L25/0232 ,  H04L27/2647

摘要： Provided are a system and method of estimating channels for a plurality of multicarrier signals in a wireless receiver. A receiver accepts a plurality of multicarrier signals, transmitted simultaneously from a plurality of transmitters, with overlapping carrier frequencies and nominally orthogonal reference signals. For each multicarrier signal, a reference signal is recovered including a plurality of adjacent subcarrier frequencies carrying predetermined symbols. A channel estimate is found across the plurality of adjacent subcarrier frequencies, for each multicarrier signal channel, by compensating for a loss of orthogonality between reference signals, in response to assuming a linear phase rotation for each channel across the plurality of adjacent reference signal subcarriers, and a constant amplitude for each channel across the plurality of adjacent reference signal subcarriers. More explicitly, the assumption of linear phase rotation and constant amplitude permits a Direction of Arrival (DoA) algorithm to be used.

摘要翻译： 提供了一种在无线接收机中估计多个多载波信号的信道的系统和方法。 接收机接收多个由多个发射机同时传输的多载波信号，具有重叠的载波频率和名义上正交的参考信号。 对于每个多载波信号，恢复包括携带预定符号的多个相邻子载波频率的参考信号。 响应于假设对于多个相邻参考信号子载波的每个信道的线性相位旋转，通过补偿参考信号之间的正交性的损失，针对每个多载波信号信道在多个相邻副载波频率上发现信道估计， 以及跨越多个相邻参考信号子载波的每个信道的恒定幅度。 更明确地说，线性相位旋转和恒定幅度的假设允许使用到达方向（DoA）算法。

公开(公告)号：US08159930B1

公开(公告)日：2012-04-17

申请号：US12616753

申请日：2009-11-11

申请人： Hemanth Sampath ,  Ravi Narasimhan

发明人： Hemanth Sampath ,  Ravi Narasimhan

IPC分类号： H04J11/00

CPC分类号： H04L5/0026 ,  H04L1/0606 ,  H04L1/0643 ,  H04L5/0007 ,  H04L5/0023 ,  H04L5/0044

摘要： Systems, devices, and techniques for MIMO (Multiple-In-Multiple-Out) based space-frequency coding can include, in at least some implementations, techniques that include receiving a selected spatial multiplexing rate M, the spatial multiplexing rate corresponding to a number of data streams for transmission on two or more antennas; for a first data tone, applying a first mapping to map a first number of data streams to a first portion of the antennas; and for a second data tone, applying a different second mapping to map a second number of data streams to a different second portion of the antennas. The first number and second number correspond to the spatial multiplexing rate.

摘要翻译： 基于MIMO（Multiple-In-Multiple-Out）的空间 - 频率编码的系统，设备和技术在至少一些实现中可以包括包括接收所选择的空间多路复用速率M的技术，对应于数字的空间复用速率 用于在两个或更多天线上传输的数据流; 对于第一数据音调，应用第一映射以将第一数量的数据流映射到天线的第一部分; 并且对于第二数据音调，应用不同的第二映射以将第二数量的数据流映射到天线的不同的第二部分。 第一个数字和第二个数字对应于空间复用率。

公开(公告)号：US08031101B2

公开(公告)日：2011-10-04

申请号：US12705416

申请日：2010-02-12

申请人： Ravi Narasimhan ,  Andrea Goldsmith

发明人： Ravi Narasimhan ,  Andrea Goldsmith

IPC分类号： H03M1/12

CPC分类号： H03M1/1042 ,  H03M1/12

摘要： A technique to mitigate in-band spurs introduced into a signal due to various board/SiP layout issues at a receiver is disclosed. The spurs can be approximated as sinusoids at different known frequencies with unknown amplitudes and phases. The technique is applicable to both single and multiple spur cancellation.

摘要翻译： 公开了一种用于减轻由于接收机处的各种板/ SiP布局问题引入到信号中的带内刺激的技术。 马刺可以近似为具有未知振幅和相位的不同已知频率的正弦波。 该技术适用于单次和多次支线取消。

公开(公告)号：US20110060956A1

公开(公告)日：2011-03-10

申请号：US12754578

申请日：2010-04-05

申请人： Andrea Goldsmith ,  Ravi Narasimhan

发明人： Andrea Goldsmith ,  Ravi Narasimhan

IPC分类号： H04L1/00 ,  H04L1/02 ,  H04L25/03

CPC分类号： H04B15/00 ,  H04B7/024 ,  H04B7/0417 ,  H04B7/0452 ,  H04B7/0465 ,  H04B7/0626 ,  H04B7/063

摘要： Interference cognitive devices are described. An interference cognitive device can be collocated with a transmitter of an interference cognitive transmitter (ICT), as receive chains or portions thereof at the ICT. An interference cognitive device can also be remote with respect to the transmitter, which operates in an interference cognitive network and receives data directly or indirectly from the interference cognitive device. The ICT uses the data to mitigate interference while continuing to operate in accordance with a performance metric.

摘要翻译： 描述干扰认知设备。 干扰认知设备可以与干扰认知发射机（ICT）的发射机并置，作为在ICT处的接收链或其部分。 相对于在干扰认知网络中操作并且从干扰认知设备直接或间接接收数据的发射机，干扰认知设备也可以是远程的。 ICT使用数据来减轻干扰，同时按照性能指标继续运行。

公开(公告)号：US07885607B1

公开(公告)日：2011-02-08

申请号：US12574262

申请日：2009-10-06

申请人： Ravi Narasimhan

发明人： Ravi Narasimhan

IPC分类号： H04B17/00

CPC分类号： H04L1/0001 ,  H04L1/20 ,  H04L25/067 ,  H04L27/2647

摘要： A transceiver includes a receiver configured to receive a radio frequency (RF) signal via a wireless communication link. The wireless link has a predetermined link characteristic. The RF signal includes a plurality of encoded Orthogonal Frequency Division Modulation (OFDM) symbols. A receive baseband processor recovers each OFDM symbol encoded within the RF signal. The baseband processor includes an estimation unit configured to continuously measure a signal quality of the wireless communication link based on each recovered OFDM symbol. A MAC layer controller is configured to selectively alter the predetermined link characteristic of the wireless link on an ongoing basis based on the continuously measured signal quality of the wireless communication link.

摘要翻译： 收发器包括经由无线通信链路接收射频（RF）信号的接收器。 无线链路具有预定的链路特性。 RF信号包括多个编码的正交频分调制（OFDM）符号。 接收基带处理器恢复在RF信号内编码的每个OFDM符号。 基带处理器包括被配置为基于每个恢复的OFDM符号连续地测量无线通信链路的信号质量的估计单元。 MAC层控制器被配置为基于无线通信链路的连续测量的信号质量来选择性地改变无线链路的预定链路特性。

公开(公告)号：US20100214145A1

公开(公告)日：2010-08-26

申请号：US12705416

申请日：2010-02-12

申请人： Ravi Narasimhan ,  Andrea Goldsmith

发明人： Ravi Narasimhan ,  Andrea Goldsmith

IPC分类号： H03M1/12

CPC分类号： H03M1/1042 ,  H03M1/12

摘要： A technique to mitigate in-band spurs introduced into a signal due to various board/SiP layout issues at a receiver is disclosed. The spurs can be approximated as sinusoids at different known frequencies with unknown amplitudes and phases. The technique is applicable to both single and multiple spur cancellation.

摘要翻译： 公开了一种用于减轻由于接收机处的各种板/ SiP布局问题引入到信号中的带内刺激的技术。 马刺可以近似为具有未知振幅和相位的不同已知频率的正弦波。 该技术适用于单次和多次支线取消。

公开(公告)号：US20180035949A1

公开(公告)日：2018-02-08

申请号：US15787742

申请日：2017-10-19

申请人： Ravi Narasimhan

发明人： Ravi Narasimhan

IPC分类号： A61B5/00 ,  A61B5/021 ,  A61B7/04

CPC分类号： A61B5/6898 ,  A61B5/0077 ,  A61B5/02125 ,  A61B5/7214 ,  A61B5/7278 ,  A61B7/00 ,  A61B7/045 ,  A61B2576/00

摘要： A method for determining blood pressure is disclosed. The method comprises determining a plurality of heart sounds using a microphone of a handheld device and determining a pulse wave using a camera of the handheld device. The method includes determining an ejection time (ET), a vascular transit time (VTT), and a heart rate from any of the plurality of heart sounds and the pulse wave. The method includes performing regression analysis on received user-specific data, the ET, the VTT, and the heart rate to determine the blood pressure.

公开(公告)号：US09814405B2

公开(公告)日：2017-11-14

申请号：US13607160

申请日：2012-09-07

申请人： Yun Yang ,  Ravi Narasimhan ,  Nima Ferdosi

发明人： Yun Yang ,  Ravi Narasimhan ,  Nima Ferdosi

IPC分类号： A61B5/0456 ,  A61B5/00 ,  A61B5/04

CPC分类号： A61B5/0456 ,  A61B5/0006 ,  A61B5/04017 ,  A61B5/7232 ,  A61B2560/0209

摘要： A method and system for R-R interval measurement of a user are disclosed. In a first aspect, the method comprises detecting an electrocardiogram (ECG) signal of the user. The method includes performing QRS peak detection on the ECG signal to obtain a low resolution peak and searching near the low resolution peak for a high resolution peak. The method includes calculating the R-R interval measurement based upon the high resolution peak. In a second aspect, a wireless sensor device comprises a processor and a memory device coupled to the processor, wherein the memory device includes an application that, when executed by the processor, causes the processor to carry out the steps of the method.