Abstract: A tag operates in an environment where transmitted interrogators are not possible or desired. High-efficiency diode rectifiers and low-power oscillators are used in combination with an energy storage element and hysteretic switch. The combination of multi-diode rectifier, low power tunnel diode oscillator, energy storage element and hysteretic switch allow for nanowatt levels of received RF power to be stored to produce micro-watts of RF transmit power. The device trickle charges off of ambient RF radiation until enough energy is stored for transmission.

Abstract: A method and system for communicating a message are disclosed. An exemplary system includes plural nodes and an exemplary information transmitter that includes a processor. The processor can detect a number of the nodes within communication range of the information transmitter as helper nodes. The processor can process a message into a number of portions as a function of the number of helper nodes detected. The processor can transmit at least one of the portions of the message to at least one of the helper nodes for wireless communication of at least one portion by the at least one helper node.

Abstract: Multiple RFID integrated circuit microradio chips are located at the feed point of an RFID tag antenna for greater, reliability, elimination of testing and to take advantage of coherent microradio operation for increased gain and power, better signal-to-noise ratios, improved range and low bit error rates.

Abstract: Stolen or lost explosives are detected by fixing micro RF transmitters in the form of RFID tags to the explosive packaging or embedding them in the explosive material itself. Moreover, the subject microradio transponders may be contained in an adhesive binder or slurry. The identity of the explosive, its place of manufacture and ownership is detectable by RFID tag interrogators strategically located along commonly used roads or railways in which the RFID tags scavenge energy from interrogation beams, with the RFID tags indicating the identity of the explosive and its origin.

Abstract: Multiple RFID integrated circuit microradio chips are located at the feed point of an RFID tag antenna for greater reliability, elimination of testing and to take advantage of coherent microradio operation for increased gain and power, better signal-to-noise ratios, improved range and low bit error rates.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

Abstract: A modem that provides efficient use of wireless network bandwidth in the presence of multiuser interference and noise is disclosed. The modem design provides for compatibility with existing network hardware and protocols so that new efficient modems may be added to the network without removing installed hardware and software.

Abstract: An RFID tag (10), containing at least two independent microscopic RFID chips (16) or microradios is programmed with the same unique identifier for each chip. The unique identifier is used in the RFID chips (16) to key the RFID chip (16) transmitting to produce outputs in the same time slot so that the outputs add coherently, thus to create an output that is identical to that of a conventional tag containing only one such chip.

Abstract: RFID tag designs and sensors are disclosed that include a dispersive antenna and exhibit greater detection ranges relative to conventional designs. The designs include, for example a transponder having including a rectifier, a radio-frequency identification (RFID) circuit for receiving and responding to interrogation signals, and a frequency dispersion element for receiving a multi-phase input signal and creating a pulse therefrom for input to the rectifier. Frequency-dispersive elements (e.g., antennas) and compatible interrogation waveforms can be used so that the rectifying diodes receive high peak voltage levels relative to the average voltage levels.

Abstract: A modem that provides efficient use of wireless network bandwidth in the presence of multi-user interference and noise comprising a multi-user detection module (115), a data formatting module (120), a control processor (125) and a demultiplexer (135).

Abstract: A coherent RFID tag design having no internal power source is disclosed. The design exhibits a longer detection range and less interference relative to conventional tag designs. The coherent RFID tag design operates in a locked or stabilized fashion, in that the frequency at which energy is parasitically coupled to the RFID tag (via its antenna) is the same as the frequency at which the RFID tag transmits information utilizing the same antenna. The RFID tag design allows a greater number of RFID tags to be deployed, without causing cross-tag interference issues and the like.

Abstract: A MUD enabled cable modem that provides efficient use of cable television network bandwidth in the presence of interference and noise is disclosed. The modem design provides for compatibility with existing network hardware and protocols so that bandwidth efficient modems configured in accordance with the principles of the present invention may be added to the network without removing installed hardware and software. A bandwidth efficient modem in the cable network head-end increases reverse link capacity from the terminals to the head end, while bandwidth efficient modems in cable network terminals increases forward link capacity from the head end to the terminals. Bidirectional bandwidth efficiency is thereby enabled.

Abstract: Wireless communication network dynamically assigning communicators to allocated channels by considering the interference and noise environment to maximize the number of communicators and effective bandwidth of the channel. The present invention provides a digital wireless modem capable of measuring interference and noise in a channel, signaling the information on a control channel, accepting dynamic channel assignments from a controlling element and demodulating signals in the presence of interference and noise. The modem uses a demodulator capable of recovering information from data signals in the presence of noise and interference stronger than the primary signal, and there is a controlling element for transmitting noise and interference measurements to a central network controller and a controlling element for determining channel assignments with the central network controller and setting the modem to the correct transmission and reception channel.

Abstract: A digital receiver automatically detects and non-coherently demodulates a multiplicity of interfering digitally modulated signals transmitted simultaneously at approximately the same carrier frequency. The receiver includes one or more antenna inputs (e.g., polarization and/or space diverse), a parameter estimator module, and a multiuser detector for estimating the data transmitted by each interfering signals and adapted to operate with at least one of a MUD algorithm with partially quantized prior information and a MUD algorithm based on prewhitened data.

Abstract: A MUD enabled cable modem that provides efficient use of cable television network bandwidth in the presence of interference and noise is disclosed. The modem design provides for compatibility with existing network hardware and protocols so that bandwidth efficient modems configured in accordance with the principles of the present invention may be added to the network without removing installed hardware and software. A bandwidth efficient modem in the cable network head-end increases reverse link capacity from the terminals to the head end, while bandwidth efficient modems in cable network terminals increases forward link capacity from the head end to the terminals. Bidirectional bandwidth efficiency is thereby enabled.

Abstract: A processing scheme for digital storage media using multi-user detection to separate tracks of data or remove interference from neighboring tracks. In one embodiment, data is written on a plurality of tracks positioned sufficiently close together so that multiple tracks are detected simultaneously by the read access sensor. Upon scanning the surface for data, the read element simultaneously receives the data signals from a plurality of tracks. Joint detection signal processing resolves the interference and data bits from the multiple sensed tracks, enabling closer packing of data with minimal guard space.

Abstract: A processing scheme for digital storage media using multi-user detection to separate tracks of data or remove interference from neighboring tracks. In one embodiment, data is written on a plurality of tracks positioned sufficiently close together so that multiple tracks are detected simultaneously by the read access sensor. Upon scanning the surface for data, the read element simultaneously receives the data signals from a plurality of tracks. Joint detection signal processing resolves the interference and data bits from the multiple sensed tracks, enabling closer packing of data with minimal guard space.

Abstract: A digital receiver automatically detects and non-coherently demodulates a multiplicity of interfering digitally modulated signals transmitted simultaneously at approximately the same carrier frequency. The receiver includes one or more antenna inputs (e.g., polarization and/or space diverse), a parameter estimator module, and a multiuser detector for estimating the data transmitted by each interfering signals and adapted to operate with at least one of a MUD algorithm with partially quantized prior information and a MUD algorithm based on prewhitened data.

Abstract: Wireless communication network dynamically assigning communicators to allocated channels by considering the interference and noise environment to maximize the number of communicators and effective bandwidth of the channel. The present invention provides a digital wireless modem capable of measuring interference and noise in a channel, signaling the information on a control channel, accepting dynamic channel assignments from a controlling element and demodulating signals in the presence of interference and noise. The modem uses a demodulator capable of recovering information from data signals in the presence of noise and interference stronger than the primary signal, and there is a controlling element for transmitting noise and interference measurements to a central network controller and a controlling element for determining channel assignments with the central network controller and setting the modem to the correct transmission and reception channel.

Abstract: An apparatus and method reducing interference between multiple frequency modulated, FM, voice transmissions present in the same frequency bandwidth by receiving a radio signal which includes a first FM voice signal to be demodulated along with one or more additional FM voice signals which are present within a modulation bandwidth of the first FM voice signal, detecting the presence of a carrier frequency signal of the first FM signal and determining a lack of modulation of the detected carrier frequency signal by a voice signal, and squelching the received signal when the carrier signal is unmodulated.