DIGITAL ZERO-IF SELECTIVITY SECTION

摘要

DIGITAL ZERO-IF SELECTIVITY SECTION A Digital Zero-IF Selectivity Section (DZISS) is disclosed. The DZISS of the present invention teaches a topology that facilitates realization in both transmitters and receivers. In the preferred low-speed embodiment, the digital filter are comprised of cascaded filter sections employing decimation co reduce the data rate. In the preferred high-speed embodiment, the digital filters are more sophisticated as at least the first filter section is decomposed to enable high-speed operation. Decimation is also employed on the high-speed embodiment to allow subsequent circuitry to operate at a lower data rate thus consuming less power. In an alternate embodiment, applicable to the low-speed and high-speed preferred embodiments, sections of the digital lowpass filters are time multiplexed effectuating a cost and space savings.