Abstract: 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.

Abstract: A system and method for scrambling and time-hopping in an ultra-wideband wireless network. In one embodiment, a wireless device includes a symbol mapper and a dynamic chip scrambler. The dynamic chip scrambler is configured to scramble each of a plurality of consecutive bursts of a time-hopped packet according to a pseudo-random scrambling sequence that varies from burst to burst.

Abstract: Apparatus and method for processing a physical layer protocol convergence (PLCP) header. In one embodiment, a wireless device includes a PLCP header processor. The PLCP header processor is configured to: process a physical layer header, process a check value based on the physical layer header, and process an error correction code based on the physical layer header and the check value. A concatenation of the physical layer header, check value, and error correction code the PLCP header processor is configured to process consists of a number of information bits that is an integer multiple of a number of information bits per symbol used to encode the PLCP header.

Abstract: 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.

Abstract: A system and method for classifying a channel with regard to delay spread in a wireless network applying orthogonal frequency division multiplexing. In one embodiment, a wireless receiver includes a channel classifier. The channel classifier is configured to compute a channel estimate corresponding to a channel traversed by a packet received by the wireless receiver. The channel classifier is also configured to partition the channel estimate into a plurality of windows. Each window corresponds to a range of time of the channel estimate. The channel classifier is further configured to assign a delay spread classification to the channel based on a distribution of energy across the windows.

Abstract: Embodiments of the invention provide a step detection. An accelerometer measurement in the form of a multi-dimensional acceleration vector is obtained. The magnitude of the accelerometer measurement is filtered using a low pass filter. A threshold for a down-crossing is provided as is a threshold for an up-crossing. A step detection is triggered if the magnitude of the accelerometer measurement is greater than or equal to the threshold for an up-crossing.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus and method for processing a physical layer protocol convergence (PLCP) header. In one embodiment, a wireless device includes a PLCP header processor. The PLCP header processor is configured to: process a physical layer header, process a check value based on the physical layer header, and process an error correction code based on the physical layer header and the check value. A concatenation of the physical layer header, check value, and error correction code the PLCP header processor is configured to process consists of a number of information bits that is an integer multiple of a number of information bits per symbol used to encode the PLCP header.

Abstract: Embodiments of the invention provide a method of adjusting a bandwidth of receivers. A plurality of outputs from a correlator engine are combined. User dynamics are sensed. Bandwidth of one or more receivers are adjusted. 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 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.

Abstract: Embodiments of the invention provide methods of calibrating 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). In one embodiment a coordinate transformation matrix using a latest position fix is created. The state variables (for user velocity) are transformed to a local navigation coordinate. The state variables of said integration filter is estimated. A blended calibrated position fix is the output of the method.

Abstract: A network coding method includes receiving a plurality of message packets each having a packet length. Encoding the plurality of message packets by applying a convolutional code across symbols in corresponding positions of the plurality of message packets obtaining a number of encoded packets. The number of encoded packets obtained being more than the number of message packets.

Abstract: 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.

Abstract: 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.

Abstract: Systems and methods for fine symbol timing estimation are disclosed herein. In one embodiment, a wireless receiver includes a differential detector, a correlator, a coarse symbol timing estimator, and a fine symbol timing estimator. The differential detector is configured to detect phase differences in a received preamble signal modulated using differential phase shift keying. The correlator is configured to correlate symbol values output by the differential detector against a reference sequence. The coarse symbol timing estimator is configured to generate a coarse symbol timing estimate, and to generate a coarse timing sample symbol index value corresponding to the coarse symbol timing estimate. The fine symbol timing estimator is configured to generate a fine symbol timing estimate that is more accurate than the coarse symbol timing estimate based on the coarse timing sample symbol index value and correlation samples at index values preceding and succeeding the coarse timing sample index value.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A communication receiver including a time domain receive filter to provide a filtered output, the filtered output including colored noise. The receiver also includes a frequency domain, fractionally-spaced equalizer (FSE) unit to receive the filtered output from the receive filter. The FSE unit determines a separate weighting factor for each subcarrier, and the weighting factor is determined based on a noise variance of the subcarrier.