SPREAD SPECTRUM COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a spread spectrum communication system which is not susceptive to noise and in which a frame structure can be identified at a reception side even if a frame synchronous signal is not transmitted.

SOLUTION: A spread code generator 42 outputs a spread code Scaior Scbiby switching them at every frame to a spread modulator 41. The spread modulator 41 spread-modulates transmission data and transmits the transmission data to a direct-current power line 2. A reference code generator 44 generates reference signals Scaiand Scbiwhich have the same code phase. Spread demodulators 43a and 43b spread-demodulate a received signal with the use of the reference signals Scaiand Scbiand output the received signal to a selector 47. A frame synchronization detector 46 identifies a frame structure based on switchover of a synchronization state of a code phase at a code phase synchronous generator 45. The selector 47 outputs reception data selecting spread demodulation data output by one of the spread demodulators 43a and 43b which is in a phase synchronous state.

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