Spectrally efficient multiplexing of O-QPSK or VSB signals using wavelet packet-based filter banks

Abstract

This paper presents fundamental principles for the design of a data transmission scheme that obtains spectrally efficient orthogonal frequency division multiplexing of digital vestigial sideband (VSB) signals. Real binary input data streams are fed into a synthesis filter bank from wavelet packet theory. Mobile satellite and personal communications applications are considered. Desirable properties of this approach are identified and discussed. A new proof of the equivalence between digital vestigial sideband and OQPSK is derived that enables convenient use of real binary signal inputs and descriptions in terms of VSB concepts. Two new closely related digital filters are added at the roots of two identical trees to obtain VSB multiplexer channels that are closely packed in frequency. Frequency and time resolution from multiresolution theory are related to bandwidth concepts. It is shown how bandwidth on demand by factors of 2 can be obtained.