Spread spectrum communication is a system suited to a communication system with deteriorated transmission quality. Recently, its application to a simplified wireless communication system has been considered for consumer communication and in other areas. The demodulation of the spread spectrum signal, in general, is complex due to the requirement of establishing the accurate synchronization for PN code in low SIN condition. A technical problem in spread spectrum communication is to realize those circuits with as simple a configuration as possible.
This paper presents a simplified configuration to solve this problem by employing two SAW devices as the matched filter and the delay line in the demodulator. The synchronization capture time also is reduced. First, the design and the result of experimental construction for the SAW matched filter which plays the core role in the demodulator are discussed. Then the construction of the small-sized demodulator using this SAW device is discussed. Finally, a discussion is presented of the synchronization capture performance, BER performance with the thermal noise and the interference immunity performance against the interference by C W and other spread spectrum signals of the proposed demodulator. It is shown that the lowcost demodulator for spread spectrum communication can be realized and is also applicable to packet communication.