SQAM: A New Superposed QAM Modem Technique

A spectral and power efficient modulation techniquesuperposed quadrature amplitude modulation (SQAM-is introduced. In SQAM, the premodulation baseband signal is a double-interval ( 2T_{s} ) raised-cosine pulse superposed with weighted single-interval (T s ) raisedcosine pulses. Our results indicate that SQAM has spectral advantages over OQPSK, QBL, and MSK, and better P(e) performance than MSK, IJF-OQPSK (or SQORC), and TFM.