Spectrally efficient modulation and spreading schemefor CDMA systems
JaeRyong Shim, Seungchan Bang · Electronics Letters · 1998
A novel modulation and spreading scheme is proposed based on the orthogonal complex rotator that outperforms the traditional PN (pseudo noise) complex QPSK method in terms of adjacent channel power. This scheme is important for hand-held terminals because it increases battery life and capacity due to reduced interference. A mathematical analysis and adjacent channel power simulation results are provided and discussed.