MULTI-BAND DIGITAL RECEIVING APPARATUS AND METHOD WITH BANDWIDTH REDUCTION

摘要

Multiple simultaneous uses of a multi-service digital receiver are made possible with a single practical analogto-digital converter (38) by translating the various service bands in frequency to form a single, generally continuous composite service band in which substantial frequency gaps (6) between the different services are eliminated. Bandwidth requirements are further reduced by a bandfolding technique in which at least one service waveband is divided about an intermediate mixing frequency (Fmix), the divided portions are overlapped so that they collectively occupy a sub-waveband with a smaller bandwidth than the original band, and the mixing frequency (Fmix) is chosen such that user-selected frequencies do not interfere with other active frequencies. Interference between non-selected active frequencies is permissible and simply ignored.