Abstract: An object locator system generates an audio signal as if emanating from the object as a user varies angular orientation and distance from an object or site to be located within an area. A computer linked to an access transceiver receives transmissions from a user wearing a headset including a transceiver and electronic compass. The compass provides a signal indicative of the user orientation. An access transceiver receives the signal and calculates the location of the user based on the time difference of arrival of the RF signal and triangulation of the user movement. An accelerometer in the headset continuously tracks user movement. The location of the object in a vertical direction is provided by a directory or other reference source stored in the computer. Based on the angular orientation, horizontal and vertical distance of the object or site relative to the user, the computer maps the location information into sounds in the form of pulse amplitude or frequency modulated sound.

Abstract: A line card connectable to a backplane connector includes a connector. The connector includes connector terminals, a subset of which are connected to an insertion monitoring circuit. The insertion monitoring circuit includes a power conductor connected to a first terminal of the subset. One or more pull up resistors are connected to the power conductor. One or more sense lines are connected to one or more second terminals of the subset. The first terminal is positioned on the card so as to be connectable to the backplane connector before the one or more second terminals. An insertion detection device is provided for detecting an insertion of the card. A state device is connected to the insertion detection device for calculating a primary insertion count from the detection of the insertion and a non-volatile memory device is connected to the state device for storing the primary insertion count.

Abstract: An N-clock system, for use for example in a ranging receiver using a Kalman filter. The clock system uses N clocks (to save power by using some clocks that consume less power) with a schedule for switching from one clock to another (so that only one clock is on at any instant of time). It uses an N-clock model that, in case of an application using clock 1 for time interval &Dgr;t1, clock 2 for time interval &Dgr;t2, . . . , and clock N for time interval &Dgr;tN, provides a state update equation for updating the N-clock system state (the state components being typically time and fractional frequency). The state update equation results from propagating the state of the assembly of N clocks (providing a single output, i.e. acting as a single clock) forward from interval to interval until the entire interval of &Dgr;t1+&Dgr;t2+ . . . +&Dgr;tN is covered.

Abstract: Compliance margin of a waveform is determined relative to a standard, indicating the extent to which the waveform either complies or fails to comply with the standard. An acquisition system captures the waveform of an applied signal in a display space, and a memory stores a representation of a series of scaled masks in the display space. Each scaled mask in the series is a version of the standard that is scaled relative to the standard according to a corresponding scale factor. A comparator determines which scaled masks in the series coincide with the waveform at one or more predesignated locations in the display space by comparing the waveform to the represented series of scaled masks at the one or more locations. An output device indicates the compliance margin of the waveform based on the corresponding scale factors of the scaled masks that coincide with the waveform at the one or more locations in the display space.