DUAL TRANSMISSION SPREAD PROCESSING CIRCUIT SYSTEM FOR CDMA COMMUNICATION APPARATUS

摘要

A CDMA communication apparatus includes a system of dual transmission spread processing circuits wherein switching control of one of the transmission spread processing circuits from an operating system to a standby system is performed momentarily by software while miniaturization and reduction in cost of the apparatus are assured. A spread processing circuit of each of dual transmission spread processing circuits is divided into two sections of an operating system spread processing section and a standby system spread processing section. Spread signals processed by the operating system spread processing section and the standby system spread processing section are addition synthesized by a first addition synthesis section and a second addition synthesis section separately from each other. An addition selection section for selecting whether or not operating system spread signals and standby system spread signals should be addition synthesized is provided in each of the transmission spread processing circuits. The addition selection section is directly controlled with a failure detection signal from a failure detection section of the other one of the dual transmission spread processing circuits.