High Efficiency Voice Activated C D MA Mobile C oininunicat ion S y s t eiii Based on Master Code Synchronization
Riccardo De Gaudenzi, Roberto Viola · 1989
In this paper we present an efficient and flexible mobile communication systeni which is operating in CDMA nonIn this paper we propose an innovative' Code Division Multi- continuous mode (voice-activated) and therefore presents the ple Access (CDMA) based Mobile System for voice (and data) efficiency advantages discussed above. The synchronization services. The system makes use of voice activation in order problelns are solved by distributing a master code in t he to increase CDMA efficiency (useful informa- forward link and using forced link activation in the return tion vs, occupied bandwidth), The synchronization problellls when no speech activity is detected. An innovative solution is proposed for minimizing the blocking probability based on and using forced link activation in the return when no speech aaelrlent of activity is detected. The blocking probabilit,y is minimized by means of multirate speech coding associated with a centralized network control. Bit Error Rate calculations show all the advantages of operating in a synchronous mode. are by distributing a master code in the forward liUk nlulti-rate speecli coding associated with the centralized nulnber of active codes,