WIRELESS FREQUENCY-DOMAIN MULTI-CHANNEL COMMUNICATIONS

摘要

A circuit for transmission and reception of multi-channel communications is disclosed. The transmitter path includes a digital modulation circuit receiving multiple channel binary data, and for each channel generating a digital representation of the data. A digital-to-analogue (D/A) conversion circuit (140-146) is provided for each data channel. Each D/A conversion circuit receives and converts respective channel digital representations to produce a resultant band limited analogue signal (148-154). The band limitation arises due to a characteristic of said channel digital representations. A bandpass filter (156-162) receives and filters each analogue channel signal. The band width to the start of the stop band of each bandpass filter is wider than a respective band limited analogue channel signal and wider than the Nyquist bandwidth arising from the sampling rate of said D/A conversion circuit. In this way, signal power in unwanted Nyquist zones is effectively removed. A frequency translation circuit (172-188) abuts the multiple channel bandpass filtered analogue signals in the frequency domain without any guard bands between adjacent channel signals.