Mode 5 detection process using phase and amplitude correlation
First Claim
1. An air traffic control system for processing a digital data stream containing a preamble and flight information data transmitted from an aircraft, comprising:
- a receiver for receiving digital radar signals from an aircraft, the receiver being arranged to provide amplitude and phase signal outputs;
a signal splitter arranged to divide the amplitude and phase signal outputs from the receiver between an odd channel and an even channel that are arranged to carry a set of odd-numbered pulses and a set of even-numbered pulses, respectively;
an odd channel data decoder connected to the signal splitter for extracting from signals encoded in the odd channel and forming an odd data streaman even channel data decoder connected to the signal splitter for extracting data from signals encoded in the even channel and forming an even data stream;
a preamble correlator connected to the odd and even channel decoders for correlating the odd and even data streams with a predefined preamble mask and detecting potential valid preambles, the preamble correlator comprising;
an odd channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the odd channel amplitude and a second input connected to the odd channel data decoder to receive decoded odd signals, the odd channel amplitude correlator being arranged to produce an odd channel amplitude correlator sum signal;
an odd channel phase correlator connected to the odd channel data decoder to receive signals that indicate the phase of odd channel signals, the odd channel phase correlator being arranged to produce an odd phase correlator sum signal;
an even channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the even channel amplitude and a second input connected to the even channel data decoder to receive decoded even signals, the even channel amplitude correlator being arranged to produce an even channel amplitude correlator sum signal; and
an even channel phase correlator connected to the even channel data decoder to receive signals that indicate the phase of even channel signals, the even phase correlator being arranged to produce an even phase correlator sum signal;
an odd channel differential phase detector in the odd channel between the signal splitter and the odd channel data decoder;
an even channel differential phase detector in the even channel between the signal splitter and the even channel data decoder; and
preamble decision logic arranged to process signals output from the preamble correlator and identify which of the potential valid preambles actually are valid.
1 Assignment
0 Petitions
Accused Products
Abstract
A receiver in a mode 5 air traffic control system provides amplitude and phase signal outputs a digital data stream containing preamble and flight information from data transmitted from an aircraft. A signal splitter divides the amplitude and phase signal outputs between an odd channel and an even channel that carry odd-numbered pulses and even-numbered pulses, respectively. An odd channel data decoder connected to the signal splitter extracts signals encoded in the odd channel and forms an odd data stream and an even channel data decoder connected to the signal splitter extracts signals encoded in the even channel and forming an even data stream. A preamble correlator correlates the odd and even data streams with a predefined preamble mask to detect potential valid preambles, and preamble decision logic processes signals output from the preamble correlator to identify which of the preambles actually are actually valid.
-
Citations
12 Claims
-
1. An air traffic control system for processing a digital data stream containing a preamble and flight information data transmitted from an aircraft, comprising:
-
a receiver for receiving digital radar signals from an aircraft, the receiver being arranged to provide amplitude and phase signal outputs; a signal splitter arranged to divide the amplitude and phase signal outputs from the receiver between an odd channel and an even channel that are arranged to carry a set of odd-numbered pulses and a set of even-numbered pulses, respectively; an odd channel data decoder connected to the signal splitter for extracting from signals encoded in the odd channel and forming an odd data stream an even channel data decoder connected to the signal splitter for extracting data from signals encoded in the even channel and forming an even data stream; a preamble correlator connected to the odd and even channel decoders for correlating the odd and even data streams with a predefined preamble mask and detecting potential valid preambles, the preamble correlator comprising; an odd channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the odd channel amplitude and a second input connected to the odd channel data decoder to receive decoded odd signals, the odd channel amplitude correlator being arranged to produce an odd channel amplitude correlator sum signal; an odd channel phase correlator connected to the odd channel data decoder to receive signals that indicate the phase of odd channel signals, the odd channel phase correlator being arranged to produce an odd phase correlator sum signal; an even channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the even channel amplitude and a second input connected to the even channel data decoder to receive decoded even signals, the even channel amplitude correlator being arranged to produce an even channel amplitude correlator sum signal; and an even channel phase correlator connected to the even channel data decoder to receive signals that indicate the phase of even channel signals, the even phase correlator being arranged to produce an even phase correlator sum signal; an odd channel differential phase detector in the odd channel between the signal splitter and the odd channel data decoder; an even channel differential phase detector in the even channel between the signal splitter and the even channel data decoder; and preamble decision logic arranged to process signals output from the preamble correlator and identify which of the potential valid preambles actually are valid. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for processing a digital data stream containing a preamble and flight information data transmitted from an aircraft for air traffic control, comprising:
-
receiving digital radar signals from an aircraft, the receiver being arranged to provide amplitude and phase signal outputs; arranging a signal splitter to divide the amplitude and phase signal outputs from the receiver between an odd channel and an even channel that are arranged to carry a set of odd-numbered pulses and a set of even-numbered pulses, respectively; connecting an odd channel data decoder to the signal splitter for extracting from signals encoded in the odd channel and forming an odd data stream connecting an even channel data decoder to the signal splitter for extracting data from signals encoded in the even channel and forming an even data stream; connecting a preamble correlator to the odd and even channel decoders for correlating the odd and even data streams with a predefined preamble mask and detecting potential valid preambles; forming the preamble correlator to include an odd channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the odd channel amplitude and a second input connected to the odd channel data decoder to receive decoded odd signals; arranging the odd channel amplitude correlator to produce an odd channel amplitude correlator sum signal; forming the preamble correlator an odd phase correlator connected to the odd channel data decoder to receive signals that indicate the phase of odd channel signals; arranging the odd phase correlator to produce an odd phase correlator sum signal; forming the preamble correlator to include an even channel amplitude correlator having a first input connected to the signal splitter to receive signals that indicate the even channel amplitude and a second input connected to the even channel data decoder to receive decoded even signals; arranging the even channel amplitude correlator to produce an even channel amplitude correlator sum signal; forming the preamble correlator to include an even phase correlator connected to the even channel data decoder to receive signals that indicate the phase of even channel signals; arranging the even phase correlator to produce an even phase correlator sum signal placing an odd channel differential phase detector in the odd channel between the signal splitter and the odd channel data decoder; placing an even channel differential phase detector in the even channel between the signal splitter and the even channel data decoder; and arranging preamble decision logic to process signals output from the preamble correlator for identifying which of the potential valid preambles actually are valid. - View Dependent Claims (8, 9, 10, 11, 12)
-
Specification