Itt Manufacturing Enterprises, Inc.

Exelis Inc.

Charles A Simmons, Jr

Dennis D McCrady

Donald John Rasmussen

Eric A Whitehill

Ning Hsing Lu

Michael Mayor

Qun Shi

Jonathan E Rose

Enhanced reception in a communication system is achieved by performing radio synchronization (SYNC) detection after multipath signal components are combined via a Rake combiner. In a communication system comprising a transmitter and a receiver, plural multipath signal components of a signal transmitted by the transmitter are received by the receiver. The plural multipath signal components are correlated with a known spreading code (e.g. a PN code). The correlated multipath signals are analyzed to identify plural correlation peaks and those correlation peaks that exceed a multipath threshold are selected. The selected correlation peaks are combined (i.e., coherently combined) to produce a combined signal. A synchronization event is declared when the combined signal exceeds an adjusted synchronization threshold and the combined signal is then decoded.

Method and apparatus for radio synchronization detection in a rake receiver

Systems and methods for refining the determination of the time of arrival (TOA) of given data. A portion of packet data is designated to be used as a pseudo TOA sequence. The packet information is modulated using, e.g., BPSK, and thereafter spread with a chipping stream known at both source and destination radios. The resulting stream includes a TOA reference pattern. On the receive side (destination radio), receive samples are despread and demodulated. The despread data is then XOR'ed with the chipping stream to re-create the TOA reference pattern. The re-created TOA reference pattern and original receive samples (previously stored) are passed through a correlator to obtain a correlation profile, which is then used for curve fitting/interpolation to accurately determine the TOA of the given received sample. Embodiments may be used in conjunction with a radio ranging system.

Ranging between radios using pseudo time of arrival sequence

A power savings technique is provided for a radio communication device. The technique involves reducing the amount of time that a receiver is powered-up during a time interval that the radio communication device may receive a transmission from another radio communication device. This time interval is referred to as a reception time interval, though it may also correspond to a time interval that the device may transmit to another device if the device is in a transmit mode. This method involves delaying enablement of the receiver for a relatively short first time interval that begins at the start of the reception time interval. When the first time interval expires, the receiver is enabled for at least a second time interval so that the device can detect whether a synchronization pattern is occurring, indicative of a radio transmission being sent for the device. The duration of the second time interval is such that it expires well before the end of the reception time interval. If the device does not detect the synchronization pattern during the second time interval, the receiver is powered-down or disabled. The durations of the first and second time intervals may be set by first and second timers, respectively. Consequently, the receiver is disabled before the end of the reception interval when there is no transmission to the device that is to be received.

Reducing power consumption in a radio device by early receiver shut down

Operational parameters for transmitting a signal over a communication channel of a network are selected by first determining RF conditions on the communication channel from a received signal transmitted over the communication channel. An initial set of parameter values is selected for transmitting the signal based on RF conditions determined from the received signal. The initial set of parameter values is used to identify other sets of parameter values as other potential candidates for transmitting the signal. The parameter values in the other sets of parameter values differ from parameter values in the initial set of parameter values by less than a predetermined amount. The expected performance of the candidate sets of parameter values is compared to determine which set of parameter values has the best expected performance among the candidate sets of parameter values. The signal is transmitted on the communication channel using the selected set of parameter values.

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Fort Wayne, IN, United States of America

Charles A Simmons, Jr