Abstract: Methods of monitoring items and/or materials from a manufacturing process. One embodiment of the invention provides a method of monitoring items and/or materials from a manufacturing process using a plurality of RFID tagged containers, and a plurality of stations associated with different portions of the manufacturing process, where each station includes an RFID reader.

Abstract: Buildings such as residences and commercial locations may have a data marker such as a barcode and/or RF device. A data marker may store/carry data indicative of an address. This allows verification of a physical address of a location and/or a name of an owner, business(es), residents, and/or employees at that location. A service provider may utilize the data marker during the provision of services. For example, when a package is to be delivered, the data marker may be scanned/interrogated for address verification and then the item may be delivered. This speeds up the tracking and delivery of goods and services. It also reduces or eliminates human error during delivery as every residence and business has an address.

Abstract: A tray (201) comprises electrically conductive material and has at least one hand-graspable fixture (203). This hand-graspable fixture comprises an electrical conductor (301) disposed in a location that is likely to be operably interacted with by a human who grasps the hand-graspable fixture. A capacitively-coupled RFID tag is then disposed on the hand-graspable fixture with a first antenna plate (303) being electrically coupled to the tray and a second antenna plate (304) that electrically couples to the electrical conductor. A corresponding tray receiving compartment (400) has a front lip (401) over which the tray must pass and upon which the tray will rest when properly disposed within the tray receiving compartment. One or more capacitively-coupled RFID tag reader antennas (402) are disposed proximal to the front lip. These antennas may be positioned to facilitate reading the capacitively-coupled RFID tag when the tray is properly disposed within the tray receiving compartment.

Abstract: The disclosed embodiments of the present invention are used to permanently disable or destruct an RFID so that it is no longer possible to read some or all of the data encoded on the RFID tag. In one method for disabling data on a radio frequency identification (RFID) tag, an RFID tag is identified and its identity is confirmed. Verification that a prerequisite event has occurred is obtained, occurrence of which is required prior to disablement of the data. A destruct instruction is transmitted to the RFID tag. The RFID tag verifies that the destruct instruction is valid and disables the data upon verifying validity of the destruct instruction. The tag may disable the data by erasing the data, disabling the data, auto-destructing, or performing any operation that makes the data unreadable.

Abstract: This invention is directed toward a series of devices designed to scare away Great Blue Herons, raccoons, and other common koi pond predators through a combination of a motion detection system which triggers an auditory and/or movement response from a variety of common enemies of koi pond predators and fanciful creatures intended to frighten koi predators. The invention teaches the combination of the motion detector with the koi predator enemy replica, such that a koi pond user can economically and efficiently protect his/her pond without adversely impacting the visual appeal of a koi pond.

Abstract: One or more switches may be coupled to a radio frequency identification (RFID) tag, so that the response of the RFID tag indicates the state of the switch(es). The RFID tag and the switch(es) may be coupled together in various ways so that the state of the switches affects the response of the RFID tag to an RFID reader.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: Enhanced physical protection against vandalism for RFID reader/writer units is provided by a relatively thick metal front or housing which also functions as the antenna element of the reader/writer. The metal front is cut or slotted to define a radio frequency antenna integral with the metal front or housing for improved physical protection and good unshielded antenna function.

Abstract: Methods and systems for automatically locating and identifying labware using radio-frequency identification (RFID) tags are described herein. The methods and systems include a plurality of RFID tags (pre-programmed with unique data codes) that are associated with labware (or labware holders). For example, the RFID tags can be embedded within the locating pegs of the labware (or labware holders). The methods and systems also include a plurality of RFID tag readers that mount near known locations of an instrument deck which receives the labware. The RFID tag readers automatically scan for the presence of RFID tags such that when a piece of labware is added to the instrument deck, and then report to a processing device the specific known location on deck where each tag was found, as well as the unique data code of each tag. Using this information, the methods and systems determine one or more of the location, orientation, and identity of the received labware.

Abstract: A system and method for observing patients in geographically dispersed health care locations. A portable monitoring station is associated with a patient assigned to a health care location. The portable monitoring station comprises monitoring equipment that monitors physiological measures of the patient. A remote command center receives the monitored data elements, accesses patient data elements indicative of a medical condition associated with the patient, and applies a patient-specific rule to selected data elements to determine whether the patient-specific rule has been contravened. The monitored equipment may further comprise video and audio equipment that captures patient video data and patient audio data and provides these data to the central command center.

Abstract: The current invention provides a remote caregiver support system which allows caregivers to provide informal care to care receivers. The systems of the current invention comprise a caregiver system and a care receiver system operating on personal computers. Each system is linked by a communications network. Preferably, the communications network is a high speed internet connection. Additionally, the current invention provides methods for delivering informal care to a care receiver remotely located from the caregiver. In the methods of the current invention, the caregiver accesses a remote caregiver support system and interacts with the care receiver providing text reminders and other informal care necessary to ensure the continued health and wellbeing of the care receiver.

Abstract: The disclosure is directed to an interactive packaging system for monitoring the usage of personal hygiene products, personal hygiene product packages, and restroom facilities. The interactive packaging system may include a plurality of usage monitoring devices each configured to detect physical stimulus associated with the usage of the product, package or facility with which the usage monitoring device is associate, and to transmit usage messages containing information relating to the detected physical stimulus. The interactive packaging system may further include a base station configured to receive the usage messages transmitted by the plurality of usage monitoring devices and to generate sensory perceptible outputs corresponding to the information contained in the usage messages. Either the usage monitoring devices or the base station may be configured to determine whether the products, packages or facilities are used appropriately based on the detected physical stimulus.

Abstract: Systems and techniques for tracking the geographic location. In one aspect, a method includes receiving timed magnetic field information descriptive of a magnetic field to which a magnetometer was subject, the magnetic field information having been collected while the magnetometer was associated with an animal, receiving timed longitude information descriptive of a longitude position of the animal, the longitude information having been collected while the magnetometer was associated with the animal, and matching the longitude information that is relevant to a first time to the magnetic field information that is relevant to the first time to determine a geographic location of the animal at the first time.

Abstract: A device for detecting a weather condition, particularly a tornado. The device includes a receiver module configured to receive electromagnetic signal from an atmosphere, particularly electromagnetic signal in the range of 1 MHz to 100 MHz. The device also includes a processing module coupled to the receiver module and configured to generate frequency spectrum data corresponding to the received electromagnetic signal, such as by performing a Fast Fourier Transform operation. Frequency spectrum data corresponding to the weather condition desired to be detected is stored in a stored data module. The device also includes a comparison module for comparing, such as by performing a cross-correlation operation, the generated frequency spectrum data and the stored frequency spectrum data in order to determine whether the weather condition is present in the atmosphere.

Abstract: The failure detecting apparatus includes an input circuit 13 connected to a temperature sensor 53 to detect various changes, for detecting the resistance of the temperature sensor 53, a monitor circuit 14 connected in parallel to the input circuit 13 for monitoring the failure of the input circuit 13, and a CPU 1 which is supplied with the resistance of the temperature sensor 53 detected by the input circuit 13 and in detecting failure of the monitor circuit 14, switches its state between the inputting state receiving a signal from the monitor circuit 14 and the outputting state sending the signal to the monitor circuit 14.

Abstract: The invention is a method and remote control apparatus for controlling an electronic device that is capable of indicating a low battery state without the need for cooperation with the electronic device. In one aspect, the invention is a remote control apparatus for controlling an electronic device comprising: a power supply having a voltage; and means to activate an indicator, wherein the activation means activates the indicator in the first way when the voltage is at or above a predefined threshold and the activation means activates the indicator in the second way when the voltage is below a predefined threshold.

Abstract: A warning system for displaying a warning that a device unit is in use includes a sign unit configured to display warning information. A device unit includes a communication module configured to provide a wireless communication between the device unit and the sign unit such that when the device unit is activated, the communication module automatically transmits a wireless warning signal to the sign unit instructing the sign unit to display the warning information.

Abstract: A wireless data communication system for a down hole environment. The system includes a housing containing a sensor, positioned within a tubular, for collecting information and processing the information, a modulator for modulating the information from the sensor into an analog signal, and a sensor antenna electrically connected to the first modulator for generating a modulated electromagnetic wave. The system further includes a probe housing, concentrically disposed within the tubular, comprising a probe antenna for receiving the modulated electromagnetic wave and generating an output, and a demodulator for demodulating the electromagnetic wave received from the sensor to a digital record. A method of wirelessly communicating between a probe and a remote sensor is also disclosed.

Abstract: The invention relates to a ‘Parking Location Reminder Device’ with means to remind drivers of the location of their parked vehicle. It comprises of housing containing a microphone, speaker and voice recorder; and is constructed in a way such that it can be attached to a vehicle key chain. Drivers record the location of their parked vehicle recorder of the said device using microphone as the audio input means. The parking location of the said vehicle is retrieved by playing back the recorded voice message using speaker as the audio output means. Means is also provided in the said device to record and playback other voice memos. Means is also provided in the ‘Parking Location Reminder Device’ for drivers to record and display/playback still images and/or video of the location of their parked vehicles.

Abstract: A circuit and method for predicting an intersection of a host aircraft flight path with the wake vortex of another aircraft.

Abstract: An encoder has a scale having an optical, magnetic or electrostatic displacement detection pattern. An encoder head detects the displacement detection pattern and generates at least two periodic signals that differ in phase, thereby to determine a displacement with respect to the scale. A center-voltage detecting unit detects only the center voltage of each periodic signal. A reference-voltage adjusting unit adjusts the center voltage detected by the center-voltage detecting unit to a predetermined reference voltage.

Abstract: A control system comprising a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet and positioned therein at least two magnetic flux sensors for sensing movement of the magnet in a given direction. The control system further comprises a monitoring arrangement for monitoring the output signal of each of the sensors and permits the input device to control the system only when the output of the sensors are within a predefined range. This multiple sensing provides a fail-safe in the event that one of the sensors generates an erroneous signal.

Abstract: A signal decoding apparatus preventing substantial noise from being produced when transmission error occurs during decoding of scalable-coded information. In this signal decoding apparatus, a coded information operation section (601) performs error detection for base layer coded information, first enhancement layer coded information and second enhancement layer coded information using transmission error detection bits. A decoding operation control section (602) performs ON/OFF control of control switches (606, 607) in accordance with pattern information indicating error detection results and bit rate patterns, and controls the sampling frequencies of sampling frequency adjustment sections (608, 609). A base layer decoding section (603), first enhancement layer decoding section (604) and second enhancement layer decoding section (605) perform decoding of coded information or frame loss compensation processing, depending on error detection results and bit rates.

Abstract: Disclosed herein is a method and system to reduce the area and power dissipation in digital filters or multipliers Compared to radix-4 Booth coding the proposed method reduces the number of partial products by one, if the input signal has certain limits on its range. One exemplary application is echo cancellation in a full duplex pulse amplitude modulation system with 10 levels (PAM-10). Echo cancellation may be achieved by calculating a digital replica of the echo from the transmission channel. The replica signal may be calculated in a finite impulse response (FIR) filter, which multiplies the transmitted signal with estimates of the echo coefficients of the transmission channel The replica signal may be subtracted from the received signal to create an echo-free receive signal. The disclosed method may reduce the number of partial products between the PAM-10 transmit signal and each echo coefficient from three, when radix-4 Booth coding is used, to two.

Abstract: A coding/decoding system and method are disclosed. Coding, as used herein, refers assigning values to cells. Information to be coded is processed stepwise in information pieces, with bitwise processing (single information bits as information pieces) as a special case. According to an illustrative embodiment, bitwise coding/decoding is disclosed. A predefined structure called a configuration is known to both the coding and decoding systems. The configuration includes a step configuration for each coding step. A step configuration is: 1) a distinction of two subsets of cells, one called inversion cells, the other called non inversion cells; 2) an assignment of at least one cell tuple consisting of at least one inversion cell and one non inversion cell each, where, for these tuples, for any preceding step configuration the tuple cells are either all inversion cells or all non inversion cells. For coding, in each step, its inversion cells are XORed with the information bit.

Abstract: A sampling rate converting circuit receives plural pieces of input data having different sampling frequencies. A plurality of FIR circuits is shared to reduce a circuit area, and, in a case where a magnification ratio of an input frequency and an output frequency is not an integer, signal deterioration due to resampling is solved. An oversampling component performs oversampling on input data Fs1 and outputs output data Fs?. An input timing timer calculates an input/input time based on an input timing signal CK1. An output timing timer and an accumulator calculate an input/output time based on an output timing signal CK? and the input timing signal CK1 and multiplies the input/output time by an oversampling multiple W to obtain a multiplied result. A divider divides the multiplied result by the input/input time to obtain a sampling position. A coefficient generator generates a filter coefficient based on the sampling position and supplies the filter coefficient to a multiplier.

Abstract: An image coding apparatus provides a run-length encoding unit RLE1 that subjects quantized coefficients which are obtained by quantizing frequency components of an image signal to a variable length coding process by using a run value Run that indicates the number of successive zero coefficients and a level value Lev that indicates a value of a non-zero coefficient following the zero coefficients. The run-length encoding unit RLE1 includes a reordering unit Lreodr for reordering level values Lev; a variable length coder LVLC for coding reordered level values ROLev by using a code table that is selected according to the value of a quantization parameter QP; a reordering unit Rreodr for reordering run values Run from high frequency component of the quantized coefficients to low frequency component; and a variable length coder RVLC for coding reordered run values RORun by using a code table that is selected according to the number of already-processed run values.

Abstract: A noise shaping quantizer having a first noise shaping quantization unit for applying a first noise shaping operation on an input signal.

Abstract: In one embodiment, a block of audio data is partitioned into N sub-blocks, and a plurality of code parameters s(0), s(1), . . . s(N?1) are determined. The N sub-blocks are entropy encoded using a plurality of entropy codes defined by the plurality of code parameters, and the code parameters are transmitted. The code parameters may be transmitted by directly transmitting s(0) representing the code parameter of the first sub-block, and transmitting a difference s(i)?s(i?1) for i=1, . . . N?1, s(i) representing the code parameter of an ith sub-block following the first sub-block.

Abstract: A method and device for decoding bin values using a pipeline architecture in a CABAC decoder are provided. The method includes reading a first context model required to decode a first bin value, from a memory; determining whether a second context model required to decode a second bin value is the same as the first context model, while decoding the first bin value using the first context model; determining whether a third context model required to decode a third bin value is the same as the second context model, while decoding the second bin value using the second context model, if it is determined that the second context model is the same as the first context model; and reading the second context model from the memory, if it is determined that the second context model is not the same as the first context model.

Abstract: Two analog signals are substantially sinusoidal and out-of-phase by about 9020 relative to each other when an element moves in a temporally uniform manner in relation to a stationary element. The two analog signals make it possible to determine the actual position of the moving element relative to the stationary element. The analog signals have a corresponding maximum frequency when the moving element moves at a maximum speed. The signals are detected by sensor units and are fed to AD converters which digitize the signals at a scanning frequency and feed corresponding digital signals to an evaluation block that is configured as a hardware circuit, the scanning frequency of the AD converters being more than twice as large as the maximum frequency. The digital signals are fed to a computing block within the evaluation block, said computing block calculating an arc tangent that corresponds to the digital signals in real time.

Abstract: Methods and apparatus are provided for decimated interpolated clock/data recovery (ICDR) to perform asynchronous sampling of a received signal. A received signal is converted to a plurality of digital samples at a downsampled rate that is lower than a rate of the received signal. The plurality of digital samples are interpolated using a plurality of parallel interpolation filters operating at the downsampled rate. An output of each parallel interpolation filter is applied to a corresponding data detector operating at the downsampled rate to generate digital data. An estimate of a timing error is generated based on the digital data. The timing error values are processed to generate an interpolation phase value that is applied to the parallel interpolation filters. A recovered clock is optionally generated, having edges corresponding to a desired synchronous sampling period.

Abstract: A method for determining a minimization factor for improving linearity of an analog-to-digital converter including a plurality of components includes the steps of: (a) Evaluating integral non-linearity response of the apparatus to identify significant departures of the response greater than a predetermined amplitude and to relate each respective significant departure with a respective identified component. (b) Determining magnitude of each significant departure. (c) Identifying a trimming factor related with each component. (d) Determining a residual gap magnitude for each significant departure. The residual gap magnitude comprises the magnitude of the respective significant departure less the trimming factor related with the identified component. (e) Determining the minimization factor as a sum of the residual gap magnitudes for a selected plurality of the identified components.

Abstract: In a multi-channel analog-to-digital converter (ADC), in which the ADC sequentially converts analog values that are input from different analog sensors, separate sample-and-hold circuits may be used to read all the analog values at the same time, and the ADC may then sequentially convert the values from each sample-and-hold circuit. This approach allows a single ADC to be used in time-critical applications that require all the analog sensor values to be measured at the same time.

Abstract: An analog-to-digital converter (ADC) having integrator dither injection and quantizer output compensation reduces the probability of unchanging code sequences that occur when the input signal and feedback signal are equal and thus no quantizer output change occurs. In particular, in modulators that are periodically reset, the dither reduces the probability of a stuck code sequence at startup. The effect of the dither is removed from the output of the ADC, either by subtracting an offset value from the result of filtering the quantizer output, or directly from the quantizer output itself.

Abstract: A D/A conversion circuit in accordance with the present invention, which is provided with a switch swD, allows a writing operation of a voltage (a true gradation voltage) to be performed at a higher speed by first applying a first voltage (a voltage close to the true gradation voltage), which is supplied without passing through a resistor element, to an output line and then applying a second voltage (the true gradation voltage), which is supplied via the resistor element, to the output line. Thus, the present invention can provide a D/A conversion circuit capable of writing display data to liquid crystal cells with higher precision at higher speed, and a semiconductor device utilizing such a D/A conversion circuit.

Abstract: A digital-to-analog converter and method for transforming a digital value into an analog signal are disclosed. The digital-to-analog converter has a voltage generator, a voltage selector, a multiplexer and a switch array. The voltage generator provides a first and second group of voltages. The voltage selector selectively outputs the first or second group of voltages according to a polarity signal. The multiplexer selectively outputs the digital value or a complementary value of the digital value according to the polarity signal. The switch array outputs one of the voltages received from the voltage selector according to the value output from the multiplexer.

Abstract: A digitizer arrangement for converting an analogue signal into a digital signal, including a first A/D converter, said first A/D converter being arranged to convert said analogue signal into a first digital signal with a first sampling rate, the first sampling rate being lower than the frequency of the analogue signal, a second A/D converter, said second A/D converter being arranged to convert said high frequency analogue signal into a second digital signal with a second sampling rate, the second sampling rate being lower than the frequency of the analogue signal, means for combining said first and second digital signals into a third digital signal with a third sampling rate that is at least a multiple of said first and second sampling rates.

Abstract: A circuit includes a successive approximation register A/D converter for performing analog to digital conversions. The register has a ground pin and a ground sense pin. The ground sense pin is connected to a ground port of the circuit. A multiplexer connects the ground sense pin of the successive approximation register A/D converter to one of a plurality of I/O ports of the circuit package. A switch selectively connects the ground sense pin of the successive approximation register A/D converter to the ground port.

Abstract: A method for passively detecting the presence of radar signal emitters, in which an ESM unit receives radar signals with a number of antennas, each antenna covering a sector of the surrounding terrain. In order to conserve bandwidth, a technique is used, in which receiving channel is slit into a number of sub-bands. Each sub-band is converted to an IF channel. The individual IF channels are combined into a common IF channel in an adder. This process is repeated once more in order to bring the signals down to baseband, where they are digitized and processed to find the direction to and the identity of the emitter source. A number of ESM units are connected to a control center. In the control center the position of the radar emitter is determined by triangulation. In addition, the identity of the emitter is determined by comparison with known emitter signatures stored in a database.

Abstract: A method of compressing phase history (PH) data includes (a) dividing PH data into multiple sub-apertures; (b) transforming the sub-apertures into multiple coarse resolution images; and (c) compressing each of the coarse resolution images. Compressing each of the coarse resolution images may include (i) selecting at least one image from the coarse resolution images to form a base image, (ii) differencing each of the coarse resolution images from the base image to form residual images, and (iii) quantizing the residual images.

Abstract: Systems and methods for presenting vertical weather information on plan view displays. An example method retrieves weather radar return information stored in a volumetric buffer and determines if a weather anomaly of the retrieved weather radar return information is above or below a predefined threshold from a present flight altitude of an aircraft. If a weather anomaly is determined to be above the threshold from the aircraft's present flight altitude, a first image is generated in a first geometric pattern and displaying the first image on a plan view display. If the weather anomaly is determined to be below the aircraft's present flight altitude, a second image is generated in a second geometric pattern and displaying the second image on the plan view display. The first geometric pattern is different from the second geometric pattern.

Abstract: A predictive collision radar system in a vehicle incorporates a first antenna and a guard antenna, the associated radiation patterns of which overlap with one another, but the radiation pattern of the guard antenna is broader than that of the first antenna. A comparison of signals from the first and guard antennas provides for rejecting targets that are not likely a threat to the vehicle. In one embodiment the first antenna is a multi-beam antenna with an electromagnetic lens, for example, either dielectric or planar, and a signal from a forward looking element thereof is compared with the signal from the guard antenna aligned therewith. In another embodiment, an electromagnetic lens is adapted to cooperate with the guard antenna so as to provide for forming the associated radiation pattern.

Abstract: A sensor suite determines location and velocity information relating to a missile threat, which is converted to missile or rocket state estimates. The state estimates are transformed into time-invariant dynamic parameters, unique for each missile type. Estimated rocket dynamic parameters are computed for each target type being considered, and compared with a reference set of rocket parameters representing different target types. The estimated rocket parameters are compared with the reference parameters in a maximum-likelihood sense, and combined using fuzzy logic to identify the rocket type and the likelihood. The identified rocket type and likelihood is used to aid in determining the future location of the missile so countermeasure can be applied.

Abstract: A system for processing radar data from two or more areas of interest is provided, such as for simultaneously processing vehicle speeds in the opposite lane in front of the patrol vehicle and in the opposite lane behind the patrol vehicle. The system includes an antenna signal processor that receives radar data from one or more radar antennae and generates speed data for a first vehicle travelling in a first direction relative to a radar observation point and a second vehicle travelling in a second direction relative to the radar observation point. A display generator system receives the speed data and user-entered display control data, and generates user-readable display data based on the speed data and the user-entered display control data.

Abstract: A method to determine a relative position between antennae comprising generating phase carrier measurements for a carrier frequency and at least three antennae including a master antenna and other antennae, generating phase integer sets based on the phase carrier measurements, and calculating a relative position between the master antenna and at least one other antenna based on the generated phase integer sets and a fixed baseline between two of the other antennae.

Abstract: A geometric shape (e.g., an inverted cone) is computed above a given ‘reference point’ defined from locations of cell sites OTHER than the cell site currently servicing a given wireless device, to provide a best-guess as to a near-future location of a mobile wireless device. Locating satellites (e.g., GPS) are culled into a preferred group and communicated to mobile devices within a particular region (e.g., serviced by a particular base station). The culled locating satellites may select visible locating satellites, or more preferably those locating satellites currently within a cone of space above the relevant base station, for communication by a mobile device within the service area of a base station. Thus, cell sites other than the one in use by the relevant wireless device may be specifically used to determine a reference point for culling the ephemeris information used to expedite Assisted GPS location determinations.

Abstract: A method and associated system for effectively increasing the number of antenna elements within a multi-element antenna system through computation of a response of “virtual” antenna elements located along an antenna array. The physical elements of the array are positioned sufficiently near each other to enable synthesis of a polynomial or other mathematical expression characterizing the response of the array to receipt of an incident waveform. Values of the responses associated with the virtual antenna elements of the array may then be determined through evaluation of the synthesized polynomial or other expression. The resultant array response values associated with the virtual and physical elements of the array are then provided to an associated receiver for processing.

Abstract: A method and apparatus for encoding information in a reference beacon signal for use in a time-difference-of-arrival/frequency-difference-of-arrival (TDOA/FDOA) geolocation system. Information is encoded in the reference beacon signal using variations in the times and frequencies of sequential reference signal transmissions. The encoded information may include an identifier associated with the transmitter of the reference beacon signal. A geolocation system receiving the reference beacon signal can thus differentiate it from non-cooperative target emissions as well as from other reference beacon signals.

Abstract: An architecture for minimizing calibration effort in an IEEE 802.11 device location measurement system. The calibration technique is based upon a regression function that produces adequately accurate location information as a function of signal strength regardless of gaps in the calibration data or minimally available data. The algorithm takes a set of signal strengths from known room locations in a building and generates a function giving (x,y) as a function of signal strength, which function may then be used for the estimation of new locations. Radial basis functions, which are simple to express and compute, are used for regression. The fact that the algorithm maps signal strength to continuous location makes it possible to skip rooms during calibration, yet still evaluate the location in those rooms.