International Business Machines Corporation

Pedro E Coronel

Wolfgang H Schott

Simeon Furrer

Beat Eugen Weiss

Jens Jelitto

Dietrich G Maiwald

Packets are periodically transmitted by a plurality of radio beacons deployed at known positions over a location estimation area. Monitoring is conducted for incoming packets. Upon receipt of a packet from a kone of the beacons, received signal strength, RSSI, is measured at each of the antenna outputs, the packet is decoded to obtain the unique identifier and the unique sequence number, and the received signal strength at each of the antenna outputs is spatially averaged. The measuring, decoding, and spatial averaging are repeated for additional packets from the kone of the beacons during a pre-defined time window T. The plurality of spatially averaged received signal strengths are temporally averaged over the pre-defined time window T, to obtain a spatially and temporally averaged value of received signal strength. The distance dfrom the apparatus to the kone of the beacons is approximated based on the spatially and temporally averaged value of received signal strength. The approximate distance dis designated as {circumflex over (d)}. This is repeated for the K beacons that have successfully transmitted packet(s) during the pre-defined time window, k=1 to K. The location of the object is estimated as an approximate intersection of spheres with radii {circumflex over (d)}. Each sphere is centered at the known position of the kone of the beacons.

Estimating location using multi-antenna radio receiver

A wireless sensor network includes a controller connected with multiple antennas for sending out a beacon signal at different instants into different directions and for receiving a sensor signal. Furthermore, the wireless sensor network comprises a sensor having a receiver connected with a sensor antenna for receiving the beacon signal, a transmitter connected with the sensor antenna for sending out the sensor signal, and a control unit which takes care that the sensor signal is transmitted after the beacon signal has been received.

Signal transmission between a sensor and a controller device in a wireless sensor network

System and program product for signal transmission between a sensor and a controller in a wireless sensor network

Provides: methods for transmission of signals between a sensor and a controller in a wireless sensor network; methods for operating the controller in the wireless sensor network; and methods for transmitting a sensor signal in the wireless sensor network from the sensor to the controller. A wireless sensor network includes a controller connected with multiple antennas for sending out a beacon signal at different instants into different directions and for receiving a sensor signal. Furthermore, the wireless sensor network comprises a sensor having a receiver connected with a sensor antenna for receiving the beacon signal, a transmitter connected with the sensor antenna for sending out the sensor signal, and a control unit which takes care that the sensor signal is transmitted after the beacon signal has been received.

Transmission between a sensor and a controller in a wireless sensor network

The present invention discloses a method and apparatus for adjusting gain setting, receiver clock frequency, and symbol timing in an OFDM radio receiver. The method is based on the reception of a preamble with known periodic training sequences transmitted prior to user data over the radio channel. By computing a periodicity metric, an inner receiver detects the presence of periodic signals in the received data sequence, provides means to set the Variable Gain Amplifier VGA gain in the radio frontend, and estimates frequency offsets between the transmit and receive clock. Matched filters are used to determine the symbol timing. A finite-state-machine schedules various tasks during the receiver startup.

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Thalwil, Switzerland

Pedro E Coronel