Abstract: A modulation system having in-phase and quadrature phase (IQ) calibration while on-line. The modulation system includes digital filters for converting I and Q data bit streams into filtered multilevel I and Q digital data streams, digital-to-analog converters, and an IQ modulator for converting the analog I and Q data streams into a modulated output signal having a representative IQ diagram having modulation states and transition locations between the modulation states. The system also includes an on-line correction data state detector, an IQ correction code, and a scalar amplitude detector. The on-line correction state detector monitors the data states in memories of the digital filters and detects the presence of particular data states that are expected to result in particular modulation states or transition locations. The amplitude detector monitors the modulated output signal and provides representative detected magnitudes.

Abstract: An electrified emergency exit device having a normally locked condition and having an operable hold off lock that is accessible from the emergency use side for maintaining an unlocked condition. The emergency exit device includes a star wheel door latch for locking or unlocking a door, a sliding catch having a lock position where the sliding catch is engaged to the door latch for locking the door and a free position where the sliding catch is disengaged from the door latch for unlocking the door, a push bar linkage operable from the emergency use side and coupled for sliding the sliding catch to the free position, a remotely operable solenoid coupled for sliding the sliding catch to the free position, the hold off lock coupled for maintaining the sliding catch in the free position, and a solenoid spring for biasing the solenoid for urging the sliding catch to the lock position when none of the push bar, solenoid, and hold off lock are actuated.

Abstract: A frequency hopping transceiver having a protocol for selecting a clear channel for exchanging QAM payload data signals. An energy level in a current channel is sounded by to determine whether it is clear or busy. When the current channel is clear an outgoing frequency shift key (FSK) handshake signal is transmitted. When the current channel is busy or an incoming handshake signal is not received, the transceiver hops to the next channel without waiting until the dwell time has elapsed for the current channel. When a channel is clear and the FSK handshake signal is received the transceiver uses a differential synchronization time for exchanging QAM acquisition signals and payload data in unison.

Abstract: A communication system, method, and multiple master and slave transceivers having automatic addressing and collision avoidance. A master transceiver is programmed with its address by a user through a host. After being turned on, a slave transceiver acquires its address as the address of the first message it receives from a master transceiver. The master and the slave transceivers then communicate in each direction and ignore other messages by using that address until the slave transceiver is turned off. When the slave transceiver is turned on again, it acquires a new address of the address of the first new message it receives from a master transceiver, not necessarily the same master transceiver. The transceivers communicate with a signal having an on-condition having different lengths for representing different symbols.

Abstract: A carrier ambiguity detector for resolving a 1/2cycle carrier phase ambiguity in an incoming GPS signal before the arrival of the next preamble by detecting a match or an inverted match between an internally stored expected data message and the incoming data in the remaining subframe before the arrival of the next preamble. The carrier ambiguity detector of the present invention includes a buffer for buffering incoming data, a data memory for storing time-tagged expected data, a data pointer for selecting certain expected data corresponding to a GPS-based time that is synchronized to the incoming data, non-inverting and inverting comparators for comparing the buffered data to the expected data, and a data compare detector coupled to the comparators for indicating a non-inverted or an inverted match for a zero degree or a one-hundred eighty degree resolution, respectively, of carrier phase information.