SIGNAL PROCESSING METHOD, SIGNAL PROCESSING DEVICE, RADIO RECEPTION DEVICE, AND COMMUNICATION RECEPTION DEVICE

摘要

It is possible to realize an ideal software reception device which can demodulate a higher-order modulation signal without losing vector information even if a carrier wave is sampled with a frequency lower than the carrier wave. A sampling frequency is set so that a phase relationship of the sampling point of an alias signal generated by sampling of a carrier with a sampling frequency lower than the carrier wave coincides with a phase relationship of the sampling point of the carrier wave. That is, the sampling frequency is set so that the carrier wave frequency "f c " and the sampling frequency "f s " satisfy the relationship f s = 4f c /(4k+1), wherein k is a positive integer. Thus, it is possible to perform undersampling of the carrier wave while holding the vector information and demodulate a higher-order modulation such as QPSK and 64QAM.