A spread spectrum CDMA communications system for communicating data and/or digitized voice between a plurality of users to a plurality of PCN units. The spread spectrum communications system is located within a same geographical region as occupied by an existing FDMA, proposed TDMA or any other mobile...http://www.google.com.tw/patents/US5351269?utm_source=gb-gplus-share專利 US5351269 - Overlaying spread spectrum CDMA personal communications system
