In order to rapidly and automatically identify the modulation level of digital amplitude modulated signals at low signal-to-noise ratio(SNR),a method of identifying the modulation levels of M-ary quadrature amplitude ...In order to rapidly and automatically identify the modulation level of digital amplitude modulated signals at low signal-to-noise ratio(SNR),a method of identifying the modulation levels of M-ary quadrature amplitude modulation(M-QAM)and M-ary amplitude shift keying(M-ASK)is proposed.In this method,wavelet transform with the optimal scale is used to identify the modulation levels of M-QAM and M-ASK signals.The performance of this method was investigated through simulations.Simulation results show that when the SNR is not lower than–4 dB,the percentage of correct identification of M-QAM is higher than 93%,and when the SNR is not lower than–10 dB,the percentage of correct identification of M-ASK is higher than 90%,using only 100 observed symbols.It shows that this method can rapidly acquire good performance at a low SNR.展开更多
文摘In order to rapidly and automatically identify the modulation level of digital amplitude modulated signals at low signal-to-noise ratio(SNR),a method of identifying the modulation levels of M-ary quadrature amplitude modulation(M-QAM)and M-ary amplitude shift keying(M-ASK)is proposed.In this method,wavelet transform with the optimal scale is used to identify the modulation levels of M-QAM and M-ASK signals.The performance of this method was investigated through simulations.Simulation results show that when the SNR is not lower than–4 dB,the percentage of correct identification of M-QAM is higher than 93%,and when the SNR is not lower than–10 dB,the percentage of correct identification of M-ASK is higher than 90%,using only 100 observed symbols.It shows that this method can rapidly acquire good performance at a low SNR.
