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June Chul Roh

June Chul Roh, Allen, TX US

Patent application numberDescriptionPublished
20100202494ULTRA WIDEBAND MODULATION FOR BODY AREA NETWORKS - A symbol modulation system applicable to a body area network is disclosed herein. The symbol modulation system includes a symbol mapper. The symbol mapper is configured to determine a time within a predetermined symbol transmission interval at which a transmission representative of the symbol will occur. The time is determined based on a value of a symbol and a value of a time-hopping sequence. The time is selected from a plurality of symbol value based time slots, and a plurality of time-hopping sequence sub-time-slots within each symbol value based time slot. The symbol mapper is configured to generate a single guard interval within the symbol transmission interval. The single guard interval is positioned to terminate the symbol transmission interval.08-12-2010
20100246639TIME-HOPPING SEQUENCE FOR BURST MODE COMMUNICATIONS - A method consisting of determining, by a symbol mapper, whether a previous burst position is below a threshold, wherein the previous burst position defines a location within a previous symbol. A determination that the previous burst position is below the threshold causes generating, by the symbol mapper, a random number in a complete set, the random number defines a current burst position, the current burst position defines a location within a current symbol and sending or receiving a value in the current burst position. A determination that the previous burst position is above the threshold causes generating, by the symbol mapper, a random number in a reduced set, the random number defines a modified current burst position, the modified current burst position defines a location within the current symbol and sending or receiving a value in the modified current burst position.09-30-2010
20100260162PHY LAYER PARAMETERS FOR BODY AREA NETWORK (BAN) DEVICES - In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment based on a constant symbol rate for BAN packet transmissions and based on M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK modulation. The PHY layer is configured to transmit and receive data in a frequency band selected from the group consisting of: 402-405 MHz, 420-450 MHz, 863-870 MHz, 902-928 MHz, 950-956 MHz, 2360-2400 MHz, and 2400-2483.5 MHz.10-14-2010
20100260232FREQUENCY-HOPPING SCHEME - A method comprises generating, by logic, a random number. The method also comprises determining a next frequency in said sequence using the random number and one or more of a minimum separation, a channel number, and a number of channels. The method further comprises hopping to the next frequency.10-14-2010
20100260236PHY LAYER PPDU CONSTRUCTION FOR BODY AREA NETWORK (BAN) DEVICES - In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment based on a constant symbol rate for BAN packet transmissions and based on M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK modulation. The PHY layer is configured to construct a physical-layer service data unit (PSDU) based on a concatenate block, an insert shortened bits block, a Bose, Ray-Chaudhuri, Hocquenghem (BCH) encoder, a remove shortened bits block, an add pad bits block, a spreader, a bit interleaver, a scrambler, and a symbol mapper.10-14-2010
20100261429PHY LAYER OPTIONS FOR BODY AREA NETWORK (BAN) DEVICES - In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment using M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK. Also, the PHY layer uses a constant symbol rate for BAN packet transmissions.10-14-2010
20110069707PACKET DETECTION AND COARSE SYMBOL TIMING FOR ROTATED DIFFERENTIAL M-ARY PSK MODULATED PREAMBLE SIGNAL - A packet detection and coarse symbol timing recovery system for preamble signal modulated with rotated differential M-ary phase shift key (PSK) modulation includes a differential detection unit, to provide a symbol signal responsive to a received signal. A preamble sequence correlator performs a preamble sequence correlation on the symbol signal to produce a correlator signal. A metric calculation unit performs a metric calculation on the correlator signal to produce a metric. A packet detection unit determines that a packet is detected and produces a sample index. A coarse symbol timing unit finds a peak of the calculated metric signal outputs a sample index for the peak as coarse symbol timing information. The sample indexes are used in processing a physical layer convergence procedure (PLCP) header and physical layer service data unit (PSDU) block.03-24-2011
20110134842Address Space Partitioning and Filtering for Discretionary Wireless Connection Response - A system and method for providing wireless communications between a medical controller hub and an implant node are disclosed. The hub transmits signals to facilitate communication connections with the node. The signals include connection invitation polls with identification parameters. A node monitors the hub's transmissions for the connection invitation polls. When a poll is detected, the node compares the identification parameters to a list of preferred identification values. If the received identification parameter is on the preferred list, and the node and hub are not already connected, then the node responds to the connection invitation poll. If the received identification parameter is not on the preferred list, then the node continues to monitor hub transmissions for other connection invitation polls that include identification parameters that are on the preferred list.06-09-2011
20110156954Position and Velocity Uncertainty Metrics in GNSS Receivers - A GNSS navigation system and navigation method for determining user position, user velocity, and improved uncertainty metrics for position and velocity. A measurement engine in an applications processor of the system determines pseudorange and delta range values over each time period for each received satellite signal, and also determines measurement noise variances for both pseudorange and delta range for the individual signals. The satellite-specific pseudorange and delta range measurement variances are used to determine the position and velocity uncertainties by a position engine, either by way of a least-squares linearization or by way of an enhanced Kalman filter. The uncertainties may be communicated to the system user, or used in generating an integrated position and velocity result from both the GNSS navigation function and an inertial navigation system result.06-30-2011

June Chul Roh, Plano, TX US

Patent application numberDescriptionPublished
20100054115System and Method for Sidelobe Suppression in Communications Systems - A system and method for sidelobe suppression in OFDM communications systems is provided. A method for transmitting an information symbol having a plurality of information sub-carriers and a plurality of active interference cancellation (AIC) sub-carriers includes generating AIC sub-carrier data based on the information to be transmitted, populating the plurality of information sub-carriers with the information, populating the plurality of AIC sub-carriers with the AIC sub-carrier data, applying baseband processing to the information symbol, thereby producing a processed symbol, and transmitting the processed symbol.03-04-2010
20100073227Detecting Lack of Movement to Aid GNSS Receivers - Embodiments of the invention provide a method of detecting movement to aid GNSS receivers. By detecting when the user is stationary, the Doppler frequency estimation can be corrected or the SNR can be boosted more both of which lead to improved performance. The embodiments allow a GNSS receiver to process signals in when the signal level would otherwise be too low—for example indoors. The embodiments can improve performance when one or more satellites are temporarily blocked but one or more satellites are still being tracked.03-25-2010
20100079334LOW-COMPLEXITY TIGHTLY-COUPLED INTEGRATION FILTER FOR SENSOR-ASSISTED GNSS RECEIVER - Embodiments of the invention provide a blending filter based on extended Kalman filter (EKF), which optimally integrates the IMU navigation data with all other satellite measurements tightly-coupled integration filter. This blending filter can be easily implemented with minor modification to the position engine of stand-alone GNSS receiver. Provided is a low-complexity tightly-coupled integration filter for sensor-assisted global navigation satellite system (GNSS) receiver. The inertial measurement unit (IMU) contains inertial sensors such as accelerometer, magnetometer, and/or gyroscopes Embodiments also include method for pedestrian dead reckoning (PDR) data conversion for ease of GNSS/PDR integration. The PDR position data is converted to user velocity measured at the time instances where GNSS position/velocity estimates are available.04-01-2010
20100097268TIGHTLY-COUPLED GNSS/IMU INTEGRATION FILTER HAVING CALIBRATION FEATURES - Embodiments of the invention provide a blending filter based on extended Kalman filter (EKF), which optimally integrates the IMU navigation data with all other satellite measurements (tightly-coupled integration filter). Two more states in the EKF for estimating/compensating the speed bias and the heading bias in the INS measurement are added. The integration filter has no feedback loop for INS calibration, and can estimate/compensate the navigation error in the INS measurement within the integration filter.04-22-2010
20100103033LOOSELY-COUPLED INTEGRATION OF GLOBAL NAVIGATION SATELLITE SYSTEM AND INERTIAL NAVIGATION SYSTEM - Techniques for loosely coupling a Global Navigation Satellite System (“GNSS”) and an Inertial Navigation System (“INS”) integration are disclosed herein. A system includes a GNSS receiver, an INS, and an integration filter coupled to the GNSS receiver and the INS. The GNSS receiver is configured to provide GNSS navigation information comprising GNSS receiver position and/or velocity estimates. The INS is configured to provide INS navigation information based on an inertial sensor output. The integration filter is configured to provide blended position information comprising a blended position estimate and/or a blended velocity estimate by combining the GNSS navigation information and the INS navigation information, and to estimate and compensate at least one of a speed bias and a heading bias of the INS navigation information.04-29-2010
20100109945LOOSELY-COUPLED INTEGRATION OF GLOBAL NAVIGATION SATELLITE SYSTEM AND INERTIAL NAVIGATION SYSTEM: SPEED SCALE-FACTOR AND HEADING BIAS CALIBRATION - Techniques for loosely coupling a Global Navigation Satellite System (“GNSS”) and an Inertial Navigation System (“INS”) integration are disclosed herein. A system includes a GNSS receiver, an INS, and an integration filter coupled to the GNSS receiver and the INS. The GNSS receiver is configured to provide GNSS navigation information comprising GNSS receiver position and/or velocity estimates. The INS is configured to provide INS navigation information based on an inertial sensor output. The integration filter is configured to provide blended position information comprising a blended position estimate and/or a blended velocity estimate by combining the GNSS navigation information and the INS navigation information, and to estimate and compensate at least one of a speed scale-factor and a heading bias of the INS navigation information.05-06-2010
20100109950TIGHTLY-COUPLED GNSS/IMU INTEGRATION FILTER HAVING SPEED SCALE-FACTOR AND HEADING BIAS CALIBRATION - Embodiments of the invention provide a tightly-coupled integration filter for inertial sensor-assisted GNSS (global navigation satellite system) receiver. The inertial measurement unit (IMU) contains inertial sensors such as accelerometer, magnetometer, and/or gyroscopes. Embodiments include blending filter based on extended Kalman filter (EKF), which optimally integrates the IMU navigation data with all other satellite measurements (tightly-coupled integration filter). The proposed blending filter includes two states for estimating/compensating the speed scale-factor and the heading bias in the INS measurement.05-06-2010

June Chul Roh, Santa Clara, CA US

Patent application numberDescriptionPublished
20090028220Robust packet detection, symbol timing, channel length estimation and channel response estimation for wireless systems - A method. The method includes producing a first signal match indication based on at least one match indication indicative of a match between at least one signal received in at least one band and a reference signal. The method also includes producing a first signal multipath combined signal based upon the first signal match indication, and detecting a first peak in the first multipath combined signal.01-29-2009