Title :
A Novel Method of Absolute Digital Demodulation
Author :
Yin, Zhendong ; Wu, Zhilu ; Ren, Guanghui ; Zhang, Zhongzhao
Author_Institution :
Dept. of Electron. & Commun. Eng., Harbin Inst. of Technol.
Abstract :
This paper proposes a digital demodulation method with all functions realized in digital processing algorithms. The bandpass digital modulation signals are transformed to direct digital sequence in the first step. After adaptive filtering, a novel bit period infimum calculation algorithm is used to classify the modulation patterns. According to the relationship between the infimums of the direct digital sequence and it´s recognition sequence, different modulation patterns can be classified easily. The probability of the correct recognition of the algorithm is higher than 95% at low signal-noise ratio condition. A 3-layer backpropagation neural network based demodulation algorithm is proposed to transform the direct digital sequence to digital baseband signal. For different patterns of the digital modulation signal, different artificial BP neural networks are designed to achieve good demodulation performance
Keywords :
adaptive filters; backpropagation; demodulation; filtering theory; neural nets; telecommunication computing; adaptive filtering; artificial BP neural networks; bandpass digital modulation signals; demodulation algorithm; digital baseband signal; digital demodulation method; digital processing algorithms; direct digital sequence; pattern modulation; period infimum calculation algorithm; recognition sequence; signal-noise ratio condition; Adaptive filters; Artificial neural networks; Backpropagation algorithms; Baseband; Demodulation; Digital modulation; Filtering algorithms; Pattern recognition; Sequences; Signal design;
Conference_Titel :
Wireless Communications, Networking and Mobile Computing, 2006. WiCOM 2006.International Conference on
Conference_Location :
Wuhan
Print_ISBN :
1-4244-0517-3
DOI :
10.1109/WiCOM.2006.149
