DEMODULATION METHOD AND DEMODULATION SYSTEM OF SPECTRAL DOMAIN COMMUNICATION SIGNAL

摘要

A demodulation method and a demodulation system of a spectral domain communication signal are disclosed. The method comprises: Step 1, a cyclic autocorrelation function estimated value processing unit calculating an estimated value of a corresponding cyclic autocorrelation function according to a continuous CDM-OFDM cyclic delay modulation signal with the length of L OFDM cycles; Step 2, a cyclic delay detection processing unit respectively calculating likelihood functions corresponding to different cyclic delay values, and obtaining a corresponding cyclic delay vector according to a maximum likelihood decision criterion; and Step 3, a cyclic modulation vector de-mapping processing unit maps the cyclic delay vector to obtain a cyclic modulation signal to be sent. The present invention can be applied to spectral domain channel multiplexing transmission, and increases the capacity of the system without affecting normal OFDM signal transmission. A block calculation manner is adopted, which greatly reduces calculation complexity and saves processing time and resources.