A synchronization circuit with correlated signal in the direct spread spectrum telecommunication system

摘要

A synchronization circuit with correlated signal is capable of generating synchronizing signals to provide a stable correlated signal when correlation processing is conducted by digital sampling and/or even when multiplexing is conducted and a low spread factor is preset in the direct spectrum telecommunication system. A discriminator (1) compares a correlated signal represented by the root of the sum of the squares of the input signals with a predetermined threshold. A processing unit (41) generates a signal when an output which does not exceed the threshold in a unique delay interval preset in a multiplexing block so that one output signal is obtained in one period of spreading. An initial synchronization circuit (2) establishes a synchronization relationship between signals from the processing unit (41). A synchronization counter (3) causes either of a correct lock counter (7) or error lock counter (6) to operate via a determining unit to synchronizing pulses in a synchronization relationship with correlation. Means for copying with a system for taking a given number of samples per one chip may be added.