Back to results
US 9,794,093 B1Granted
Passive classification of radio frequency signals
AssigneeHarris Corporation
InventorsBrian J. Haman, Raphael Lyman, Allan Weiner, Abdelmoula Elharti
Life of this patent
Estimating the term…
Abstract
System for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard includes a radio frequency receiver and a computer processor operatively coupled to the receiver. The system evaluates physical parameters of the RF signals and obtains an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be normally transmitted. The extracted bit sequence information is compared to a plurality of known bit sequences specified for DRS in an LTE uplink communication.
Claims20
A method for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with an LTE communication standard, comprising:
- selectively acquiring radio frequency (RF) signals originating within a predefined geographic area;
- evaluating physical parameters of the RF signals, including frequency information and signal timing information, to identify at least one RF signal that has at least one physical characteristic which is known to correspond to an LTE uplink transmission;
- selectively classifying the identified at least one RF signal as a potential UE generated uplink communication;
- extracting from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard, the DRS comprising a known bit sequence permitted by the LTE communication standard for channel estimation;
- comparing the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- and
- selectively re-classifying the identified at least one RF signal as a UE generated uplink operating in accordance with an LTE standard if the comparing satisfies a predetermined correlation condition.
4 more elements
A method for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard, comprising:
- selectively acquiring radio frequency (RF) signals originating within a predefined geographic area;
- evaluating physical parameters of the RF signals, including frequency information and signal timing information to identify at least one potential UE generated uplink communication;
- extracting from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard;
- comparing the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- selectively classifying the acquired RF signal as a UE generated uplink operating accordance with an LTE standard if the comparing satisfies a predetermined correlation condition;
- wherein the evaluating of the signal timing information comprises recovering a slot timing directly from the acquired RF signal to determine a beginning and an end time of each time slot in the acquired signal.
3 more elements
A method for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard, comprising:
- selectively acquiring radio frequency (RF) signals originating within a predefined geographic area;
- evaluating physical parameters of the RF signals, including frequency information and signal timing information to identify at least one potential UE generated uplink communication;
- extracting from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard;
- comparing the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- selectively classifying the acquired RF signal as a UE generated uplink operating accordance with an LTE standard if the comparing satisfies a predetermined correlation condition;
- and
- determining the sum of the energy present in each Resource Block of the acquired RF signal, and comparing the sum to a first threshold value to determine if a potential LTE uplink signal is present in that Resource Block.
4 more elements
A method for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard, comprising:
- selectively acquiring radio frequency (RF) signals originating within a predefined geographic area;
- evaluating physical parameters of the RF signals, including frequency information and signal timing information to identify at least one potential UE generated uplink communication;
- extracting from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard;
- comparing the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- and
- selectively classifying the acquired RF signal as a UE generated uplink operating accordance with an LTE standard if the comparing satisfies a predetermined correlation condition;
- wherein the comparing comprises comparing the extracted bit sequence with the plurality of known bit sequences specified for DRS in an uplink communication over a range of possible Cyclic Shifts between 0 and 2π.
4 more elements
A system for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with an LTE communication standard, comprising:
- a radio frequency receiver configured to selectively acquire radio frequency (RF) signals originating within a predefined geographic area;
- and
- a computer processor configured to:
- evaluate physical parameters of the RF signals, including frequency information and signal timing information, to identify at least one RF signal that has at least one physical characteristic which is known to correspond to an LTE uplink transmission;
- selectively classify the identified at least one RF signal as a potential UE generated uplink communication;
- extract from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard, the DRS comprising a known bit sequence permitted by the LTE communication standard for channel estimation;
- compare the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- and
- selectively re-classify the identified at least one RF signal as a UE generated uplink operating in accordance with an LTE standard if the comparing satisfies a predetermined correlation condition.
6 more elements
A system for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard, comprising:
- a radio frequency receiver configured to selectively acquire radio frequency (RF) signals originating within a predefined geographic area;
- and
- a computer processor configured to:
- evaluate physical parameters of the RF signals, including frequency information and signal timing information to identify at least one potential UE generated uplink communication;
- extract from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard;
- compare the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- and
- selectively classify the acquired RF signal as a UE generated uplink operating accordance with an LTE standard if the comparing satisfies a predetermined correlation condition;
- wherein the evaluating of the signal timing information performed by the computer processor further comprises recovering a slot timing directly from the acquired RF signal to determine a beginning and an end time of each time slot in the acquired signal.
6 more elements
A system for passively classifying a signal as a user equipment (UE) generated uplink communication in accordance with in an LTE communication standard, comprising:
- a radio frequency receiver configured to selectively acquire radio frequency (RF) signals originating within a predefined geographic area;
- and
- a computer processor configured to:
- evaluate physical parameters of the RF signals, including frequency information and signal timing information to identify at least one potential UE generated uplink communication;
- extract from the potential UE generated uplink communication information concerning an extracted bit sequence contained in a time slot in which a Demodulation Reference Signal (DRS) would be transmitted by the UE in an actual uplink communication in accordance with the LTE communication standard;
- compare the information concerning the extracted bit sequence with information concerning a plurality of known bit sequences specified for DRS in an LTE uplink communication;
- and
- selectively classify the acquired RF signal as a UE generated uplink operating accordance with an LTE standard if the comparing satisfies a predetermined correlation condition;
- wherein the comparing performed by the signal processor further comprises comparing the extracted bit sequence with the plurality of known bit sequences specified for DRS in an uplink communication over a range of possible Cyclic Shifts between 0 and 2π.
6 more elements
Dependencies are inferred from the claim text.