Abstract: A method and apparatus for activity tracking based on time domain and frequency domain processing are disclosed. Embodiments according to the present invention are used to improve the accuracy of activity detection and step counting. The activity tracking starts from sample collection to generate 3-D accelerometer data. By pre-processing, the 3-D accelerometer data is calibrated and filtered. Then, the dominant component is calculated and statistical attributes or features used for activity detection are extracted. The statistical attributes are derived from time domain sensor data, frequency domain transformed data, or both. A classifier is developed using representative training data set. The activity detector determines the current activity status based on the statistical attributes and the classifier. To further refine the activity, post-processing is performed on the activity status.

Abstract: A system for counting steps comprising a 3-D accelerometer is disclosed. The system also includes a pre-processor module coupled to the 3-D accelerometer and a dominant component computation unit coupled to the pre-processor module. The dominant component computation unit is configured to identify a dominant component in an output of the 3-D accelerometer. The system further includes a step counter for counting a number of steps using the output of the dominant component computation unit. The step counter includes a Fast Fourier Transform (FFT) module and a direct current (DC) remover module to remove a static component from the output of the FFT module. The step counter also includes a derivative filter and a zero crossing detector.

Abstract: The system, apparatus and method of the present invention provides a single carrier block transmission with guard interval as a means of communications over multi-path channels that enables frequency domain equalization, and therefore, has many of the advantages of OFDM, but does not have some of the drawbacks such as high PAPR and the need for high resolution ADCs. While the use of guard intervals in single carrier communications enables low complexity detection of the signal, it reduces bandwidth efficiency. The present invention improves the bandwidth efficiency by adjusting the length of the guard interval adaptively. Also, by allowing both time-domain and frequency domain equalizations, besides improving bandwidth efficiency, the inventions allows for great flexibility in receiver design.

Abstract: A system for counting steps comprising a 3-D accelerometer is disclosed. The system also includes a pre-processor module coupled to the 3-D accelerometer and a dominant component computation unit coupled to the pre-processor module. The dominant component computation unit is configured to identify a dominant component in an output of the 3-D accelerometer. The system further includes a step counter for counting a number of steps using the output of the dominant component computation unit. The step counter includes a Fast Fourier Transform (FFT) module and a direct current (DC) remover module to remove a static component from the output of the FFT module. The step counter also includes a derivative filter and a zero crossing detector.

Abstract: A method and apparatus for encoding a block-based communication system header. A physical layer header and a medium access control header of the block-based communication system header are encoded to generate parity bits, wherein the PHY layer header includes at least cyclic prefix mode bits. Parity bits are appended to the PHY layer header and the MAC layer header to generate a bit vector. The bit vector is divided into at least two data blocks, wherein a first data block includes at least the CP mode bits. A predefined number of tail bits are appended to each data block. The two data blocks are mapped into at least two symbols, wherein the first data block is mapped to a first symbol, such that the first symbol is a first header symbol being transmitted.

Abstract: A method and apparatus for activity tracking based on time domain and frequency domain processing are disclosed. Embodiments according to the present invention are used to improve the accuracy of activity detection and step counting. The activity tracking starts from sample collection to generate 3-D accelerometer data. By pre-processing, the 3-D accelerometer data is calibrated and filtered. Then, the dominant component is calculated and statistical attributes or features used for activity detection are extracted. The statistical attributes are derived from time domain sensor data, frequency domain transformed data, or both. A classifier is developed using representative training data set. The activity detector determines the current activity status based on the statistical attributes and the classifier. To further refine the activity, post-processing is performed on the activity status.

Abstract: A first wireless device communicates data to a second wireless device. The first wireless device employs at least one of a first interleaving scheme and a first sub-carrier mapping scheme to produce a first data packet from a first plurality of data bits, and transmits the first data packet to the second wireless device. When the first data packet is not received correctly by the second wireless device, then the first wireless device employs at least one of a second interleaving scheme and a second sub-carrier mapping scheme to create a second data packet from the first plurality of data bits, and transmits the second data packet to the second wireless device.

Abstract: A method and apparatus for encoding a block-based communication system header. A physical layer header and a medium access control header of the block-based communication system header are encoded to generate parity bits, wherein the PHY layer header includes at least cyclic prefix mode bits. Parity bits are appended to the PHY layer header and the MAC layer header to generate a bit vector. The bit vector is divided into at least two data blocks, wherein a first data block includes at least the CP mode bits. A predefined number of tail bits are appended to each data block. The two data blocks are mapped into at least two symbols, wherein the first data block is mapped to a first symbol, such that the first symbol is a first header symbol being transmitted.

Abstract: A method (400) and apparatus for encoding a block-based communication system header. A physical (PHY) layer header and a medium access control (MAC) header of the block-based communication system header are encoded to generate parity bits, wherein the PHY layer header includes at least cyclic prefix (CP) mode bits (S410). Parity bits are appended to the PHY layer header and the MAC layer header to generate a bit vector (S420). The bit vector is divided into at least two data blocks, wherein a first data block includes at least the CP mode bits (S430). A predefined number of tail bits are appended to each data block (S440). The two data blocks are mapped into at least two symbols, wherein the first data block is mapped to a first symbol, such that the first symbol is a first header symbol being transmitted (S450).

Abstract: A method and system is provided for detecting the presence of a DVB (digital video broadcasting) transmission with frequency offsets. The method includes receiving an RF (radio frequency) signal in a selected channel; creating samples from the received RF signal; estimating a frequency offset of the samples; correcting the samples with the estimated frequency offset; correlating the corrected samples with a reference signal; and comparing a correlation result with a threshold value. The frequency offset estimation includes selecting a set of three or more pilots that are boosted continual pilots transmitted at fixed sub-carrier locations in all symbols; transforming the received samples to the frequency domain; determining locations of maxima in the transformed samples, the maxima corresponding to the pilots in the set; and comparing the determined locations with the expected pilot locations in the set.

Abstract: A method and system is provided for detecting the presence of a DVB (digital video broadcasting) transmission. The method includes receiving an RF (radio frequency) signal in a selected channel (1101); creating signal samples from the received RF signal (1102); creating averaged samples from the signal samples, each averaged sample being an average of a predetermined number of signal samples that are separated by a minimum pilot pattern repetition period from one to the next signal sample (1103); correlating the averaged samples with a reference sequence (1104); and comparing a correlation result with a threshold correlation value (1105).

Abstract: A method and system for scheduling and protecting quiet periods (QP) in a quiet zone (105) for incumbent signal (121) detection in a wireless communications system. The communication system includes a plurality of wireless networks (103, 104), each of the plurality of wireless networks contains at least a master device (101, 401) and a client device (111, 411). In each of the plurality of wireless networks, the master device (101, 401) transmits a beacon (402) that contains a QP schedule (500) and a reservation of a time slot (405) for the client device (411). The client device (111, 411) transmits a request-to-quiet (RTQ) message (412) during the time slot, wherein the RTQ message (412) includes the client device's QP schedule information. The master and client devices within the quiet zone (105) keep quiet during scheduled quiet periods according to the QP schedule information contained in the received beacons and RTQ messages.

Abstract: A detector module (100) is operable in a cognitive radio device and capable of determining channel occupancy. The detector module comprises a sensor (110) for sensing incumbent signals at a variable sensing threshold, wherein the sensor generates a first occupancy indication indicating whether the channel includes an incumbent signal having a sensing metric above the variable sensing threshold; a geo-location unit (120) for generating a second occupancy indication based on a location of the detector module; and a decision unit (130) for generating an occupancy decision based on both the first occupancy indication and the second occupancy indication.

Abstract: Methods and apparatus for a scalable network of heterogeneous devices are disclosed. The network may include segment controllers in communication with a remote management system and a plurality of heterogeneous devices such as, for example, lighting fixture nodes and sensors. The segment controllers may transmit sensor data from the sensors to the remote management system. The segment controllers may also transmit control data to the lighting fixture nodes and, optionally, to one or more supplementary nodes. At least some of the control data may be based on data sent from the remote management system and, optionally, the segment controller may generate at least some of the control data independently of the remote management system.

Abstract: A method and system is provided for detecting the presence of a DVB (digital video broadcasting) transmission. The method includes receiving an RF (radio frequency) signal in a selected channel (1101); creating signal samples from the received RF signal (1102); creating averaged samples from the signal samples, each averaged sample being an average of a predetermined number of signal samples that are separated by a minimum pilot pattern repetition period from one to the next signal sample (1103); correlating the averaged samples with a reference sequence (1104); and comparing a correlation result with a threshold correlation value (1105).

Abstract: A method and system is provided for detecting the presence of a DVB (digital video broadcasting) transmission with frequency offsets. The method includes receiving an RF (radio frequency) signal in a selected channel (901); creating samples from the received RF signal (902); estimating a frequency offset of the samples (903); correcting the samples with the estimated frequency offset (904); correlating the corrected samples with a reference signal (905); and comparing a correlation result with a threshold value (906). The frequency offset estimation includes selecting a set of three or more pilots that are boosted continual pilots transmitted at fixed sub-carrier locations in all symbols (1001); transforming the received samples to the frequency domain (1002); determining locations of maxima in the transformed samples, the maxima corresponding to the pilots in the set (1003); and comparing the determined locations with the expected pilot locations in the set (1004).

Abstract: A method (400) and apparatus for encoding a block-based communication system header. A physical (PHY) layer header and a medium access control (MAC) header of the block-based communication system header are encoded to generate parity bits, wherein the PHY layer header includes at least cyclic prefix (CP) mode bits (S410). Parity bits are appended to the PHY layer header and the MAC layer header to generate a bit vector (S420). The bit vector is divided into at least two data blocks, wherein a first data block includes at least the CP mode bits (S430). A predefined number of tail bits are appended to each data block (S440). The two data blocks are mapped into at least two symbols, wherein the first data block is mapped to a first symbol, such that the first symbol is a first header symbol being transmitted (S450).

Abstract: A method and system for scheduling and protecting quiet periods (QP) in a quiet zone (105) for incumbent signal (121) detection in a wireless communications system. The communication system includes a plurality of wireless networks (103, 104), each of the plurality of wireless networks contains at least a master device (101, 401) and a client device (111, 411). In each of the plurality of wireless networks, the master device (101, 401) transmits a beacon (402) that contains a QP schedule (500) and a reservation of a time slot (405) for the client device (411). The client device (111, 411) transmits a request-to-quiet (RTQ) message (412) during the time slot, wherein the RTQ message (412) includes the client device's QP schedule information. The master and client devices within the quiet zone (105) keep quiet during scheduled quiet periods according to the QP schedule information contained in the received beacons and RTQ messages.

Abstract: A detector module (100) is operable in a cognitive radio device and capable of determining channel occupancy. The detector module comprises a sensor (110) for sensing incumbent signals at a variable sensing threshold, wherein the sensor generates a first occupancy indication indicating whether the channel includes an incumbent signal having a sensing metric above the variable sensing threshold; a geo-location unit (120) for generating a second occupancy indication based on a location of the detector module; and a decision unit (130) for generating an occupancy decision based on both the first occupancy indication and the second occupancy indication.

Abstract: A first wireless device communicates data to a second wireless device. The first wireless device employs at least one of a first interleaving scheme and a first sub-carrier mapping scheme to produce a first data packet from a first plurality of data bits, and transmits the first data packet to the second wireless device. When the first data packet is not received correctly by the second wireless device, then the first wireless device employs at least one of a second interleaving scheme and a second sub-carrier mapping scheme to create a second data packet from the first plurality of data bits, and transmits the second data packet to the second wireless device.