Wireless Frequency-Domain Multi-Channel Communications

A method for transmitting data comprising:

• forming a limited duration digital representation of multiple input data channels;
• converting each said digital representation to an analogue signal that is band limited within at least one Nyquist zone for each channel;
• bandpass filtering each analogue signal for each channel, wherein the band width to the start of the stop band of each said bandpass filter being wider than a respective band limited analogue signal and wider than the Nyquist bandwidth arising from the sampling rate of said conversion, whereby signal power in unwanted Nyquist zones is effectively removed;
• abutting said bandpass filtered analogue signals in the frequency domain without any guard bands;
• and
• wirelessly transmitting said abutted bandpass filtered analogue signals.

A transceiver comprising:

• (a) a transmitter circuit including:
• a digital modulation circuit receiving multiple channel binary data, and for each channel generating a digital representation;
• a digital-to-analogue (D/A) conversion circuit for each data channel, each said D/A conversion circuit receiving and converting respective said channel digital representations to produce a resultant analogue signal that is band limited within at least one Nyquist zone, said band limitation being dependent on a characteristic of said channel digital representations;
• a bandpass filter receiving and filtering each analogue signal, the band width to the start of the stop band of each said bandpass filter being wider than a respective band limited analogue signal and wider than the Nyquist bandwidth arising from the sampling rate of said D/A conversion circuit, whereby signal power in unwanted Nyquist zones is effectively removed;
• and
• a frequency translation circuit for abutting said multiple channel bandpass filtered analogue signals in the frequency domain without any guard bands between adjacent channel signals;
• and
• (b) a receiver circuit including:
• a radio frequency circuit to receive a multiple channel radio frequency signal, said multiple channels being abutted;
• a frequency translation circuit for separating said received multiple channel signals by frequency translation;
• an analogue-to-digital (A/D) conversion circuit for each channel, each said A/D conversion circuit converting a respective analogue channel signal to a digital representation;
• and
• a digital demodulation circuit receiving said channel signal digital representation and generating channel symbols therefrom, and generating multiple channel binary data from said symbols.

A circuit comprising:

• a digital modulation circuit receiving multiple channel binary data, and for each channel, converting one or more channel binary data values to a symbol value, and generating a summed time sequence of digital data values implementing constituent impulse responses at a predetermined centre frequency for each said symbol value;
• a digital-to-analogue (D/A) conversion circuit for each data channel, each said D/A conversion circuit receiving and converting respective said channel time sequences to produce a resultant analogue signal at a predetermined sampling frequency, wherein said predetermined sampling frequency is 4/3 times said centre frequency;
• a bandpass filter receiving and filtering each analogue signal, whereby signal power in unwanted Nyquist zones is effectively removed;
• and
• a frequency translation circuit for abutting said multiple channel bandpass filtered analogue signals in the frequency domain without any guard bands between adjacent channel signals.