Patent ID: 8855187

Claim:
A signal processing method for enhancing a dynamic range of a signal, the method comprising: a) forming an attenuated signal from an input signal; b) filtering each of the input and the attenuated signals such that a sum of their bandwidths is not more than a bandwidth of a transmission channel; prior to step (b), converting the input signal and the attenuated signal to digital signals; c) modulating a first one of the filtered input signal and the filtered attenuated signal, whereby the filtered input signal and the filtered attenuated signal occupy respective non-overlapping frequency ranges within the bandwidth of the transmission channel, wherein the modulation of step (c) is performed by multiplying the first one of the filtered input signal and the filtered attenuated signal with a digital signal having a width of a plurality of bits synthesised to approximate a sine wave with a frequency of half a sampling frequency of the digital filtered input signal and digital filtered attenuated signal; and d) combining the modulated signal with the second one of the filtered input signal and the filtered attenuated signal to form a composite output signal.