System having an analog to digital converter (ADC) and a digital signal processor

A method of processing an input signal comprising;

• generating, by an analog to digital converter, a superposition signal, said superposition signal generated by under-sampling an input signal at a first sampling frequency, wherein said input signal that is input to the analog to digital converter has a bandwidth and said sampling frequency (Fsample) is less than a Nyquist rate for the bandwidth of the input signal;
• digitally processing, by a digital signal processor, said superposition signal to separate said superposition signal into a plurality of bitstreams, each of the plurality of bitstreams corresponding to information in a different one of a plurality of separable, distinct frequency bands within the input signal, wherein the information in the superposition signal for at least one of said plurality of bitstreams is present in the input signal at frequencies greater than the sampling frequency;
• and
• outputting said plurality of bitstreams.

A system comprising:

• an apparatus configured to receive an input signal having a bandwidth;
• a first device configured to transmit a first signal comprising a first frequency part of said input signal, wherein the first frequency part comprises a part, in the frequency domain, of the frequencies that form the input signal, wherein the first signal is configured to be transmitted with a first encoding scheme;
• a second device configured to transmit a second signal comprising a second frequency part of said input signal, wherein the second frequency part comprises a part, in the frequency domain, of the frequencies that form the input signal different to the first frequency part, wherein the second signal is configured to be transmitted with a second encoding scheme and wherein the first signal is encoded such that it is separable from the second signal and is transmitted contemporaneously;
• wherein the apparatus is configured to receive the input signal formed of the first signal and the second signal and comprises:
• an analog to digital converter configured to generate a superposition signal, said superposition signal generated by under-sampling the input signal at a sampling frequency (Fsample) wherein said sampling frequency (Fsample) is less than a Nyquist rate for the bandwidth of the input signal;
• a digital signal processor configured to digitally processes said superposition signal to separate said superposition signal into a plurality of bitstreams, each of the plurality of bitstreams corresponding, respectively, to information in each of the separable first signal and the second signal from said superposition signal, wherein the information in the superposition signal for at least one of said plurality of bitstreams is present in the input signal at frequencies greater than the sampling frequency;
• and
• outputting said plurality of bitstreams.