1 results about "Quaternary" patented technology

The invention relates to a cascade-mode-based quaternary minimum-shift keying (MSK) modulation method and a cascade-mode-based quaternary MSK modulation device. A modulator comprises a first serial parallel converter and a second serial parallel converter; a demodulator comprises a 2FSK (frequency shift keying) modulation module and a 2MSK modulation module; the upper braches of the first serial parallel converter are connected with the second serial parallel converter by an EOR (exclusive OR) arithmetic unit and a differential coder in turn; the lower braches of the first serial parallel converter are connected with the input end of the 2MSK modulation module through the 2FSK modulation module and a band-pass filter in turn; the upper branch of the second serial parallel converter is connected with the cophase component end of the 2MSK modulation module through a delayer; the lower branch of the second serial parallel converter is connected with the orthogonal component end of the 2MSK modulation module; the output end of the 2MSK modulation module is connected with the band-pass filter; and the lower branch of the first serial parallel converter is connected with the EOR arithmetic unit. Due to the adoption of the method and the structure, quaternary MSK signals, which have constant envelope, continuous phases, minimum bandwidth and strict orthogonality, can be provided.