公开(公告)号：US10484224B2

公开(公告)日：2019-11-19

申请号：US15942614

申请日：2018-04-02

Applicant: Texas Instruments Incorporated

Inventor： Jaiganesh Balakrishnan ,  Sarma Sundareswara Gunturi ,  Pankaj Gupta ,  Indu Prathapan

IPC: H04L27/26

Abstract: The disclosure provides a circuit. The circuit includes an IFFT (inverse fast fourier transform) block. The IFFT block generates a modulated signal in response to a data signal. A clip logic block is coupled to the IFFT block, and generates a clipped signal in response to the modulated signal. A first subtractor is coupled to the clip logic block and the IFFT block, and subtracts the modulated signal from the clipped signal to generate an error signal. A cyclic filter is coupled to the first subtractor, and filters the error signal to generate a filtered error signal. A second subtractor is coupled to the cyclic filter and the IFFT block. The second subtractor subtracts the filtered error signal from the modulated signal to generate a processed signal.

公开(公告)号：US10371528B2

公开(公告)日：2019-08-06

申请号：US14323823

申请日：2014-07-03

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Jayawardan Janardhanan ,  Jaiganesh Balakrishnan

IPC: G01C21/12 ,  G01C22/00 ,  G01C21/16 ,  A61B5/11 ,  G01P15/18

Abstract: Devices and methods for pedestrian navigation are disclosed. In an embodiment, a device includes an accelerometer sensor configured to sense acceleration components associated with a device motion in a plurality of axes of the accelerometer sensor. The acceleration components include stride frequency components and step frequency components. The device includes a processing module communicably associated with the accelerometer sensor. The processing module is configured to process at least a portion of the acceleration components to determine an estimated attitude associated with the device motion with respect to the accelerometer sensor. The processing module is configured to filter out the step frequency components by blocking the stride frequency components. The processing module is further configured to determine the estimated attitude based on the step frequency components to thereby mitigate a bias in the estimated attitude associated with a lateral sway of the device motion.

公开(公告)号：US10305451B1

公开(公告)日：2019-05-28

申请号：US15839265

申请日：2017-12-12

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sundarrajan Rangachari ,  Jaiganesh Balakrishnan ,  Jawaharlal Tangudu ,  Srinivas Kumar Reddy Naru

IPC: H03H17/02 ,  H03H17/06

Abstract: In some embodiments, a multiplier-based programmable filter comprises a pre-scaling circuit, a first multiplier circuit coupled to a first output of the pre-scaling circuit and a second output of the pre-scaling circuit, and a second multiplier circuit coupled to the first output of the pre-scaling circuit and the second output of the pre-scaling circuit. In some embodiments, the multiplier-based programmable filter also comprises a first adder coupled to a first output of the first multiplier circuit and a second output of the first multiplier circuit, a second adder coupled to a first output of the second multiplier circuit and a second output of the second multiplier circuit, first register coupled to an output of the first adder and an input of the second adder, and a second register coupled to an output of the second adder.

公开(公告)号：US20190013818A1

公开(公告)日：2019-01-10

申请号：US16029539

申请日：2018-07-06

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sthanunathan Ramakrishnan ,  Sashidharan Venkatraman ,  Jaiganesh Balakrishnan ,  Sreenath Narayanan Potty

IPC: H03M1/12 ,  H03M1/06 ,  H03F1/02

CPC classification number: H03M1/121 ,  H03F1/0244 ,  H03M1/0626 ,  H03M1/1215 ,  H03M1/129 ,  H03M1/185

Abstract: An interleaved ADC receives an RX signal attenuated by a DSA based on an active DSA setting, within a range of DSA settings (DSA setting range) corresponding to selectable attenuation steps, the DSA setting range partitioned into a number of DSA setting subranges (DSA subranges). The ADC includes an IL mismatch estimation engine in the digital signal path, with an estimation subrange blanker, and an IL mismatch estimator. The estimation subrange blanker is coupled to receive the IADC data stream, and responsive to a DSA subrange allocation signal to select, in each of successive aggregation cycles, IADC data corresponding to an active DSA setting that is within an allocated DSA subrange (DSA active data within an DSA allocated subrange). The IL mismatch estimator aggregates, during each aggregation cycle, IL mismatch estimation data based on the selected DSA active data within the DSA allocated subrange, generates an estimate of IL mismatch (IL mismatch estimate) based on the aggregated IL mismatch estimation data, generates IL mismatch correction parameters based on the aggregated IL mismatch estimation data, and generates IL mismatch estimate uncertainty data corresponding to an uncertainty in the IL mismatch estimate used to generate the associated IL mismatch correction parameters for the DSA allocated subrange. A DSA statistics collector to collect a distribution of DSA settings over a pre-defined time period (DSA setting distribution statistics). An estimation subrange allocator coupled to receive DSA setting distribution statistics, and the IL mismatch estimate uncertainty data, and to provide to the estimation subrange blanker the DSA subrange allocation signal according to a pre-defined allocation strategy.

公开(公告)号：US09985650B2

公开(公告)日：2018-05-29

申请号：US15392491

申请日：2016-12-28

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Jawaharlal Tangudu ,  Suvam Nandi ,  Jaiganesh Balakrishnan

IPC: H03M7/00 ,  H03M7/30 ,  H03H17/06

CPC classification number: H03M7/6047 ,  H03D7/165 ,  H03D2200/0056 ,  H03H17/0664 ,  H03M7/3059

Abstract: A digital down converter includes a low resolution mixer, a decimation filter, and a high resolution mixer. The low resolution mixer is configured to receive a digitized radio frequency signal, and apply a first down conversion to the radio frequency signal to produce an intermediate frequency signal. The decimation filter is coupled to the low resolution mixer. The decimation filter is configured to receive the intermediate frequency signal, and reduce a sampling rate of the intermediate frequency signal to produce a decimated intermediate frequency signal. The high resolution mixer is coupled to the decimation filter. The high resolution mixer is configured to receive the decimated intermediate frequency signal, and apply a second down conversion to the decimated intermediate frequency signal to produce a down converted signal.

公开(公告)号：US09510319B2

公开(公告)日：2016-11-29

申请号：US14565878

申请日：2014-12-10

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sthanunathan Ramakrishnan ,  Sashidharan Venkatraman ,  Ravi Krishna Bhat ,  Jaiganesh Balakrishnan ,  Saket Thukral

IPC: H04W64/00

CPC classification number: H04W64/006 ,  H04W84/12

Abstract: Several methods and systems for location estimation are disclosed. In an embodiment, the method includes performing a primary wireless scan to identify a first set of access points at a user location associated with a first user location estimate. A secondary wireless scan is performed at pre-defined time intervals subsequent to the primary wireless scan. A set of access points is identified corresponding to each secondary wireless scan. The method further comprises detecting a presence or an absence of user motion based on a number of shared access points between the first set of access points and a set of access points corresponding to each secondary wireless scan. A current user location is estimated to be the first user location estimate if the user motion is detected to be absent, or a second user location estimate computed based on geolocation signals if the user motion is detected to be present.

Abstract translation: 公开了几种用于位置估计的方法和系统。 在一个实施例中，该方法包括执行主无线扫描以识别与第一用户位置估计相关联的用户位置处的第一组接入点。 在主要无线扫描之后，以预定义的时间间隔执行辅助无线扫描。 与每个次级无线扫描相对应的一组接入点。 该方法还包括基于第一组接入点与对应于每个辅助无线扫描的一组接入点之间的共享接入点的数量来检测用户运动的存在或不存在。 如果检测到用户运动不存在，估计当前用户位置是第一用户位置估计，或者如果检测到用户运动存在，则基于地理位置信号计算的第二用户位置估计。

公开(公告)号：US20160174185A1

公开(公告)日：2016-06-16

申请号：US14565878

申请日：2014-12-10

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sthanunathan Ramakrishnan ,  Sashidharan Venkatraman ,  Ravi Krishna Bhat ,  Jaiganesh Balakrishnan ,  Saket Thukral

IPC: H04W64/00

CPC classification number: H04W64/006 ,  H04W84/12

Abstract: Several methods and systems for location estimation are disclosed. In an embodiment, the method includes performing a primary wireless scan to identify a first set of access points at a user location associated with a first user location estimate. A secondary wireless scan is performed at pre-defined time intervals subsequent to the primary wireless scan. A set of access points is identified corresponding to each secondary wireless scan. The method further comprises detecting a presence or an absence of user motion based on a number of shared access points between the first set of access points and a set of access points corresponding to each secondary wireless scan. A current user location is estimated to be the first user location estimate if the user motion is detected to be absent, or a second user location estimate computed based on geolocation signals if the user motion is detected to be present.

Abstract translation: 公开了几种用于位置估计的方法和系统。 在一个实施例中，该方法包括执行主无线扫描以识别与第一用户位置估计相关联的用户位置处的第一组接入点。 在主要无线扫描之后，以预定义的时间间隔执行辅助无线扫描。 与每个次级无线扫描相对应的一组接入点。 该方法还包括基于第一组接入点与对应于每个辅助无线扫描的一组接入点之间的共享接入点的数量来检测用户运动的存在或不存在。 如果检测到用户运动不存在，估计当前用户位置是第一用户位置估计，或者如果检测到用户运动存在，则基于地理位置信号计算的第二用户位置估计。

公开(公告)号：US20150295749A1

公开(公告)日：2015-10-15

申请号：US14693416

申请日：2015-04-22

Applicant: Texas Instruments Incorporated

Inventor： Raghu Ganesan ,  Bijoy Bhukania ,  Jaiganesh Balakrishnan

IPC: H04L27/38 ,  H04B1/00

CPC classification number: H04L27/3863 ,  H04B1/0039

Abstract: Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.

Abstract translation: 在正交RF接收机中存在I / Q失配的情况下，本文公开的装置和方法执行增益，限幅和相位补偿。 由于低分辨率ADC中I＆Q信号之间的限幅差异，增益和相位失配加剧。 更强的信道臂中的信号比另一个信道臂中的较弱的信号差分地被削波。 本文实施例在增益失配计算的迭代期间执行削波操作，以平衡I和Q通道臂之间的限幅。 增益补偿系数迭代收敛，建立限幅电平，流经网络的数据得到增益和限幅补偿。 然后从增益和削波补偿采样数据确定补偿相位角和相位补偿系数。 所得到的相位补偿系数被应用于增益和限幅校正的接收机数据，以产生增益，限幅和相位补偿的数据流。

公开(公告)号：US09140802B2

公开(公告)日：2015-09-22

申请号：US13958765

申请日：2013-08-05

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sachin Bhardwaj ,  Jaiganesh Balakrishnan ,  Sriram Murali

IPC: G01S19/49 ,  G01C21/16

CPC classification number: G01S19/49 ,  G01C21/16

Abstract: In the present disclosure, an error in the velocity and position computed from a three dimensional IMU measurement is reduced confined by computing an auxiliary speed in a drive direction of a vehicle from an angular velocity measurement and a lateral acceleration measurement. The auxiliary speed is then compared with the speed computed from the acceleration measurement. The auxiliary speed is provided as the speed of the vehicle mounted with the IMU when the absolute difference between the auxiliary speed and the speed computed from the acceleration measurement in the drive direction is above a threshold. The auxiliary speed is computed when the vehicle is detected to be in a curved motion. According to another aspect of the present disclosure, the bias errors are determined when the vehicle is in a steady state, at rest or in a straight line motion. The bias errors are used to obtain the accurate auxiliary measurement.

Abstract translation: 在本公开中，通过从角速度测量和横向加速度测量计算车辆的驱动方向上的辅助速度来限制从三维IMU测量计算的速度和位置的误差。 然后将辅助速度与从加速度测量计算的速度进行比较。 当辅助速度和从驱动方向上的加速度测量计算的速度之间的绝对差高于阈值时，辅助速度被提供为安装有IMU的车辆的速度。 当检测到车辆处于弯曲运动时，计算辅助速度。 根据本公开的另一方面，当车辆处于稳定状态，静止或直线运动时，确定偏置误差。 偏置误差用于获得准确的辅助测量。

公开(公告)号：US20150039154A1

公开(公告)日：2015-02-05

申请号：US13958765

申请日：2013-08-05

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sachin Bhardwaj ,  Jaiganesh Balakrishnan ,  Sriram Murali

IPC: G01S19/49

CPC classification number: G01S19/49 ,  G01C21/16

Abstract: In the present disclosure, an error in the velocity and position computed from a three dimensional IMU measurement is reduced confined by computing an auxiliary speed in a drive direction of a vehicle from an angular velocity measurement and a lateral acceleration measurement. The auxiliary speed is then compared with the speed computed from the acceleration measurement. The auxiliary speed is provided as the speed of the vehicle mounted with the IMU when the absolute difference between the auxiliary speed and the speed computed from the acceleration measurement in the drive direction is above a threshold. The auxiliary speed is computed when the vehicle is detected to be in a curved motion. According to another aspect of the present disclosure, the bias errors are determined when the vehicle is in a steady state, at rest or in a straight line motion. The bias errors are used to obtain the accurate auxiliary measurement.

Abstract translation: 在本公开中，通过从角速度测量和横向加速度测量计算车辆的驱动方向上的辅助速度来限制从三维IMU测量计算的速度和位置的误差。 然后将辅助速度与从加速度测量计算的速度进行比较。 当辅助速度和从驱动方向上的加速度测量计算的速度之间的绝对差高于阈值时，辅助速度被提供为安装有IMU的车辆的速度。 当检测到车辆处于弯曲运动时，计算辅助速度。 根据本公开的另一方面，当车辆处于稳定状态，静止或直线运动时，确定偏置误差。 偏置误差用于获得准确的辅助测量。