Abstract: 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.

Abstract: According to an embodiment of the present invention, geolocations of multiple unknown radio frequency (RF) signal sources are determined using three-dimensional (3-D) geolocation techniques. The three-dimensional (3-D) geolocation techniques obtain reliable geolocation estimates of radio frequency (RF) emitters based on energy or received signal strength (RSS) of emitter transmitted signals and based on their time differences of arrival (TDOAs) at various sensor locations. The energy based geolocations and the time difference of arrival (TDOA) geolocations are combined to determine an overall set of geolocations for multiple unknown radio frequency (RF) signal sources. The geolocation information is used to track and monitor the locations of the multiple emitters.

Abstract: According to an embodiment of the present invention, a three-dimensional (3-D) energy-based emitter geolocation technique determines the geolocation of a radio frequency (RF) emitter based on energy or received signal strength (RSS) of transmitted signals. The technique may be employed with small unmanned air vehicles (UAV), and obtains reliable geolocation estimates of radio frequency (RF) emitters of interest.

Abstract: Enhanced reception in a communication system is achieved by applying a time domain generated time-reversed channel response to signals transmitted from a group of transmitter to a group of receivers. The time-reversed channel response is generated from a radio frequency channel response derived from signals previously received from the group of receivers, but reversed in the time domain. The time-reversed channel response is convolved with an information signal that when transmitted in a coordinated fashion from the group of transmitters, the signals arrive at each receiver in the group of distant receiving communication devices at approximately the same time where the signals coherently combine, thereby increasing signal power at the receivers. This permits detection at a greater range or with a lower bit error rate. In addition, the many-to-many configuration enables signal power from each transmitter to be focused temporarily and spatially on each receiver.

Abstract: Systems and methods are provided herein that extend well-known direction finding (DF) and geolocation (GEO) concepts and approaches to a plurality of RF sensors to form a System of Systems (SoS) DF-GEO approach. The RF sensors may be collocated or spatial separated, and are able to exchange or share DF/GEO data. The SoS DF-GEO approach opportunistically leverages both on-board and off-board processing resources and DF-GEO measures for cooperative processing, situation awareness sharing, and performance optimization. The off-board processing resources and DF-GEO measures may be shared via networking. Thus, the SoS DF-GEO approach primarily bases measurements upon RSS or energy obtained from a one-antenna system or from a two-antenna system of a single RF sensor, as well as from other RF sensors via networking. By adopting the innovative SoS DF-GEO concept approach as described herein, optimized DF-GEO performance can be obtained by using the system of systems approach.

Abstract: According to an embodiment of the present invention an emitter geolocation technique determines the geolocation of a radio frequency (RF) emitter using pair-wise line-of-bearing intersections that are derived from signal-to-noise ratios of transmitted signals received at a sensor. The technique may be employed with ground based vehicle or small unmanned air vehicles (UAV), and obtains reliable geolocation estimates of radio frequency (RF) emitters of interest.

Abstract: According to an embodiment of the present invention jamming energy is allocated to a plurality of emitters based on a three-dimensional (3-D) emitter geolocation technique that determines the geolocation of radio frequency (RF) emitters based on energy or received signal strength (RSS) and/or time differences of arrival (TDOAs) of transmitted signals. The three-dimensional (3-D) emitter geolocations are used to rank emitters of interest according to distance and available radio frequency (RF) jamming energy is allocated to the emitters in rank order. The techniques may be employed with small unmanned air vehicles (UAV), and obtains efficient use of jamming energy when applied to radio frequency (RF) emitters of interest.

Abstract: 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.

Abstract: Enhanced reception in a communication system is achieved by applying a time domain generated time-reversed channel response to signals transmitted from a group of transmitter to a group of receivers. The time-reversed channel response is generated from a radio frequency channel response derived from signals previously received from the group of receivers, but reversed in the time domain. The time-reversed channel response is convolved with an information signal that when transmitted in a coordinated fashion from the group of transmitters, the signals arrive at each receiver in the group of distant receiving communication devices at approximately the same time where the signals coherently combine, thereby increasing signal power at the receivers. This permits detection at a greater range or with a lower bit error rate. In addition, the many-to-many configuration enables signal power from each transmitter to be focused temporarily and spatially on each receiver.

Abstract: According to an embodiment of the present invention an emitter geolocation technique determines the geolocation of a radio frequency (RF) emitter using pair-wise line-of-bearing intersections that are derived from signal-to-noise ratios of transmitted signals received at a sensor. The technique may be employed with ground based vehicle or small unmanned air vehicles (UAV), and obtains reliable geolocation estimates of radio frequency (RF) emitters of interest.

Abstract: According to an embodiment of the present invention jamming energy is allocated to a plurality of emitters based on a three-dimensional (3-D) emitter geolocation technique that determines the geolocation of radio frequency (RF) emitters based on energy or received signal strength (RSS) and/or time differences of arrival (TDOAs) of transmitted signals. The three-dimensional (3-D) emitter geolocations are used to rank emitters of interest according to distance and available radio frequency (RF) jamming energy is allocated to the emitters in rank order. The techniques may be employed with small unmanned air vehicles (UAV), and obtains efficient use of jamming energy when applied to radio frequency (RF) emitters of interest.

Abstract: According to an embodiment of the present invention, geolocations of multiple unknown radio frequency (RF) signal sources are determined using three-dimensional (3-D) geolocation techniques. The three-dimensional (3-D) geolocation techniques obtain reliable geolocation estimates of radio frequency (RF) emitters based on energy or received signal strength (RSS) of emitter transmitted signals and based on their time differences of arrival (TDOAs) at various sensor locations. The energy based geolocations and the time difference of arrival (TDOA) geolocations are combined to determine an overall set of geolocations for multiple unknown radio frequency (RF) signal sources. The geolocation information is used to track and monitor the locations of the multiple emitters.

Abstract: According to an embodiment of the present invention, a three-dimensional (3-D) energy-based emitter geolocation technique determines the geolocation of a radio frequency (RF) emitter based on energy or received signal strength (RSS) of transmitted signals. The technique may be employed with small unmanned air vehicles (UAV), and obtains reliable geolocation estimates of radio frequency (RF) emitters of interest.