A fpga-based signal processing method for anti-same-channel interference of marine radar

Abstract

The invention discloses a ship radar anti-same-frequency-interference signal processing method based on an FPGA. Video echo signals are processed through analog-digital conversion and then subjected to three-pulse staggering time sequence processing, meanwhile, anti-interference variables are superposed, and dynamic synchronous interference asynchronization is achieved; the echo signals processed through synchronous interference asynchronization are subjected to improved three-pulse reverse asynchronous processing; finally, sliding window accumulation is performed on the echo signals subjected to reverse asynchronous processing. Compared with the prior art, the ship radar anti-same-frequency-interference signal processing method based on the FPGA has the advantages that on the basis of a random circuit and mode correction, dynamic staggering of the radar transmission period is achieved through time sequence design; the capacity for detecting small targets and targets in interference units is improved through improved three-pulse reverse asynchronous correlation; through the sliding window accumulation processing, same-frequency interference residues are further reduced, and the signal-to-noise ratio of detection is increased.

Description

technical field [0001] The invention relates to the field of ship navigation radar, in particular to an anti-co-frequency interference signal processing method for ship radar based on FPGA. Background technique [0002] At present, the functions of ship navigation radar have far exceeded the initial target detection and ranging, and have been widely used in navigation to avoid collisions and rescue at sea, as well as to complete the navigation of ships entering and leaving ports, and to maintain formation in groups. significant meaning. Not only large and ocean-going ships must be installed, but small ships such as fishing boats and yachts are also commonly installed with navigation radars. [0003] In the offshore area, especially near the port, since the frequency of the ship's navigation radar that is turned on at the same time is the same or similar, there will be serious co-frequency interference, and the more the number and the closer the distance, the more serious th...

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Problems solved by technology

Although this simple anti-asynchronous processing can achieve a certain interference suppression effect, there are the following problems: First, it is difficult to establish a multi-period comparison criterion, especially because the operating environment of the marine navigation radar determines that the target pulse interval has a large fluctuation characteristic. It is more difficult to deal with small targets with low signal-to-noise ratio; secondly, when there is a large amount of co-channel interference, the selection of the stagger amount cannot fully ensure that the interference has a sufficiently large amplitude difference in adjacent multiple periods, and the interference will produce residual; thirdly, If the target and the interference coincide on the distance unit in the processing cycle, that is, when the target is submerged in the interference, because the output of the interference unit is prohibited, the target is also lost while the interference is eliminated

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