Aiming to meet the requirement of modulation recognition in high order and to solve the difficulty of
modulation recognition in low signal-to-noise ratio environment in 6G communication, a modulation recognition al
gorithm based on multi-criteria fusion and intelligent decision was proposed by combining artificial intelligence tech
nology and modern signal processing technology. The algorithm was divided into two parts. Multi-criteria fusion net
work and intelligent decision network. The multi-criteria fusion network calculated the higher-order cumulative ex
tensions of the standard modulation signals, traversed all the potential thresholds by using local optimal solutions,
and determined the judgment thresholds by Gini coefficient and the entropy of certainty gain. The intelligent deci
sion network adopted a CART architecture to recognize the modulation format of unknown signals using the deter
mined judgment thresholds, and the model was iterative optimized using a pruning algorithm to obtain the finally op
timal decision tree, forming a modulation recognition algorithm based on multi-criteria fusion and intelligent deci
sion making.
Experimental results showed that the algorithm could accurately recognize 16QAM, 64QAM,
128QAM, 1024QAM, 2PSK, 4PSK, 8PSK, 2FSK, 4FSK at 0 dB SNR, and the comprehensive recognition accu
racy reached 99. 4%. Compared with other methods, the modulation recognition accuracy and the types of recogniz
able modulation were improved.