Patent ID: 7957454

Claim:
A transmitter that transmits a transmission signal to a receiver in a spread spectrum communications system, comprising: a spread modulation portion spreading a transmission signal with a spread code into spread data; an RZ conversion portion converting the spread data into an RZ signal; and an impulse sequence conversion portion multiplying the RZ signal by an impulse sequence to convert the RZ signal to an impulse radio signal including a series of impulses in the spread data, and transmits the transmission signal converted into the impulse radio signal to the receiver, wherein the receiver demodulates the transmission signal without establishing synchronization with the impulse radio signal wherein a demodulation portion that selects, from the n buffers, a buffer in which a signal level of the transmission signal stored into each buffer corresponds with a spread code used for the spreading of the transmission signal by the transmitter, and demodulates the transmission signal based on the signal level stored into the selected buffer.