An improved sequence design for code-division multiple access (CDMA) communications generating complex four-phase pseudo-random code sequences which may be directly mapped to a quadrature phase shift keying (QPSK) signal constellation....http://www.google.com.tw/patents/US6337875?utm_source=gb-gplus-share專利 US6337875 - Method and apparatus for generating complex four-phase sequences for a CDMA communication system
