Multi-code CDMA wireless personal communications networks

Proposes a code division multiple access (CDMA) based system that can provide a smooth migration path to PCS, either from a digital cellular system (IS-95) or from a wideband CDMA system, to serve both isochronous and asynchronous applications. A unified digital bandwidth on demand platform is realized by allocating multiple codes (on demand), and hence increased capacity, to users. This approach, dubbed multi-code CDMA (MC-CDMA), will enable efficient delivery of all services made possible by digital cellular, CDPD, and other PCS technologies. Since a large variety of services (voice, data, image, and perhaps video) is expected in future wireless networks, users with very different, and time-varying, source rates will have to be accommodated. MC-CDMA is a wireless system whose rate (which is proportional to the number of codes assigned to the user) and service are dynamically matched to users' needs and can evolve from commercial digital cellular systems. This system retains the CDMA advantage in combating multipath and does not require significant modifications of the radio frequency (RF) circuitry. The dynamic, packet-like capacity access enabled by MC-CDMA will allow users to access the base station at different source rates, and when all other users are idle, will provide peak rate access to a single user.