A New Data Modulation and Demodulation Scheme for THz Communications

In this paper, a new data modulation and demodulation scheme are proposed for the terahertz (THz) communications. The new data modulation scheme is named as M-ary pi/2 amplitude phase shift keying (APSK) modulation, which modulates data bits to data symbols with two kinds of phases separated by pi (180°) and then rotates the data symbols by pi/2 in alternating symbol. So the new data modulation scheme can resist the large phase noise (PN) and reduce the peak-to-average power ratio (PAPR). Accordingly, a new data demodulation scheme is also designed to apply for the receiver based on Log-likelihood ratio (LLR) in a polar coordinate instead of conventional cartesian coordinate. The simulation results show that the proposed data modulation and demodulation scheme can achieve superior PAPR and BLER performance in THz frequency bands.