| 摘要 |
The present invention relates to a method for direct sequence spreading of a data sequence (d(t)) or a modulated data sequence (s(t)). The method yields better spectral properties than conventional methods for data transmission using direct sequence spread spectrum (DSSS) and is also suitable for systems where one wants to conceal the existence of transmission, so-called stealth radio. This is achieved by one or more spreading sequence generators (21) in the transmitter and the corresponding sequence generators (31) in the receiver emitting new output data at a rate which essentially exceeds the one required for obtaining in the transmitter a certain desired spread bandwidth, the spreading sequence or spreading sequences (c(t)) being caused to bandspread the data sequence (d(t)) or the modulated data sequence (s(t)), and the desired spread bandwidth being obtained by filtering in band-limiting filters (22). |
