초록 ▼

In a system with a spread spectrum transmitter and receiver employing composite spreading codes, the transmitter spreads, in a spreading part, a baseband modulated signal by a short code from a short code generator and a long code from a long code generator with a longer chip period than that of the

In a system with a spread spectrum transmitter and receiver employing composite spreading codes, the transmitter spreads, in a spreading part, a baseband modulated signal by a short code from a short code generator and a long code from a long code generator with a longer chip period than that of the short code and then transmits the spread baseband modulated signal. The receiver despreads a spread baseband received signal in a receiving part by a pair of short and long codes in one despreading part to obtain a baseband modulated signal of a direct path and despreads the spread baseband received signal by the pair of short and long codes delayed by a multipath delay time difference in the other despreading part to obtain a baseband modulated signal of a delayed path, and the baseband modulated signals thus obtained are diversity-detected to obtain a detected baseband signal.

대표청구항 ▼

[ What is claimed is:] [1.] A spread spectrum receiver employing composite spreading codes, comprising:a receiving part for receiving a transmitted signal spectrum-spread by short and long codes to obtain a spread baseband received signal;clock signal generating means for generating a first clock si

[ What is claimed is:] [1.] A spread spectrum receiver employing composite spreading codes, comprising:a receiving part for receiving a transmitted signal spectrum-spread by short and long codes to obtain a spread baseband received signal;clock signal generating means for generating a first clock signal of a predetermined first clock period and a second clock signal of a second clock period N times longer than said first clock period, said N being larger than 1 but smaller than 8 and said second clock period being set longer than a predetermined delay time of a propagation path;a short code generating means for repeatedly generating at least one short code of a chip period of the same length as that of said first clock period and of a first repetition period in synchronization with said first clock signal for each chip, said first repetition period of said short code being set equal to a symbol period;a long code generating means for repeatedly generating a long code of a chip period longer than the chip period of said short code and of a second repetition period longer than said predetermined delay time of a propagation path and said first repetition period in synchronization with said second clock signal for each chip, the number of chips of said long code being greater than that of said short code;a multipath separating part including a predetermined number of despreading parts each provided corresponding to one of a plurality of multipath components including a direct path component and at least one delayed path component, for despreading said spread baseband received signal from said receiving part by a pair of the short code and the long code in synchronization with said first and second clock signals, respectively at timing corresponding to an individual multipath and for outputting a despread signal corresponding to one of said plurality of multipath components; anda diversity type detecting part for diversity-detecting despread signals from said predetermined number of despreading parts to detect a digital signal.