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Proposal of band-limited divided-spectrum single carrier transmission for dynamic spectrum controlled access in ISM band

A single carrier transmission system is proposed. It is a dynamic spectrum access system designed for ISM bands where various radio systems are operating. The proposed system divides the spectrum of the single carrier modulation into a few “subspectra” and allocates them for fragmented vacant spectra, which are called “white space” in the band. Not FFT/IFFT operations for each signal block with cyclic prefix, but band-limiting filters, of cosine roll-off characteristics for example, are adopted for the spectrum dividing in order to reduce ACPR (or ACLP, adjacent channel leakage power ratio). Simulation results show that PAPR (peak-to-average power ratio) of the transmitted signal can be reduced by limiting the number of the spectrum division within a few pieces. The proposed system utilizes the remaining vacant spectra thoroughly so that it copes with the increasing demand of spectrum use expected in ISM bands toward the ubiquitous network world in the near future.