Digital orthogonal filtering is generally used formultiplexing two signals to one channel, and it is used inthe mode division multiplexing transmission of twodegenerate modes to reduce the influence of signalcrosstalk between channels from the perspective ofintelligent frequency hopping, so as to obtain theintelligent fiber mode channel hopping sequence ofjammer and target transmitter. In the mode divisionmultiplexing transmission system, the fiber mode channelis not ideal, and the transmission of signals ( )i tand( )q twill be affected by the channel response ( )h t .Therefore, the signal output of the channel matched filterat the receiver can be expressed as: