A low-power CMOS chipset for spread spectrum communications

摘要: In future personal communication services, high-bandwidth multimedia data will be delivered over wireless pico-cellular networks to high densities of users. The system described here is designed simultaneously supply 1 Mb/s up 50 users in a single cell, requiring bandwidth excess Mb/s. use spread-spectrum techniques, particular direct sequence code-division multiple access (CDMA), provides multiple-access strategy maintain parallel, separate streams real-time all users, and reduce sensitivity multipath, narrow band fades, interference present the radio environment. Three chips standard digital 0.8 /spl mu/m CMOS technology implement critical parts spread spectrum transceiver: modulator; analog receiver front-end ADC; baseband processor. transmit transmitter based loosely on US IS-95 cellular CDMA standard, but at more than an order magnitude higher date rate.