A novel demodulation algorithm based on sampling with aliasing

It is a challenging problem to demodulate a linear modulation signal. The sampling theorem plays an important role in the software radio for designing the receiver. The theory of bandpass sampling gives a criterion to sample a signal without aliasing in the frequency domain. Using a different sampling frequency, the sampled signal has many different structures of the spectrum. Taking advantage of this characteristic, this paper presents a demodulation algorithm based on sampling the aliasing signal by analyzing the spectrum of some kind of linear modulation signal in an intuitionistic way. Analysis shows that this demodulation algorithm has great advantages over the traditional ones in antialiasing filter design and the design of receiver's structure. This algorithm has been successfully used in our underground mine communication system.