Multi-band, multi-function integrated transceiver

Abstract

A communications system operating in one or more frequency bands of various number of channels per band (for a total of N channels), and a novel transceiver for receiving these multiple bands of signals. The transceiver comprises an antenna and RF front end for each said band, a separate RF to IF downconverter for each said band. The IF for each band is centered at a succession of frequencies F such that the spectra for each band are non-overlapping, with the center frequencies. Analog-to-digital converter sampling rate is chosen such that one band is centered at baseband, and one or more other bands are centered at a specific relationship with the sampling rate such that each band is individually downconverted to baseband by appropriate selection of tap weight multiplying sequences (such as alternating +/− sequence for the case of F equal to one-fourth the sampling rate). An analog-to-digital converter converts analog signals to digital signals from the combiner. A digital downconverter converts the digital signals to baseband signals and a single digital processor sequentially time shared among all the bands and channels.