Signal modulation for radiofrequency communications

A signal modulation device for providing an output signal to a radio frequency front-end, the device comprising:

• an input for receiving a complex input signal comprising an in-phase component signal and a quadrature-phase component signal,
• a sigma-delta modulator for modulating the complex input signal at an oversampling clock rate into an intermediary signal, wherein the intermediary signal takes a first finite number of quantized complex states,
• a symbol mapping table for mapping the quantized complex states of the intermediary signal to predefined quantized symbols each encoding a pulse train segment of the output signal,
• a numerical oscillator for generating a phase signal oscillating at a selected carrier frequency, wherein the phase signal takes a second finite number of quantized states,
• wherein the symbol mapping table comprises a predefined quantized symbol for each quantized complex state of the intermediary signal and each quantized state of the phase signal, and operates at each oversampling clock period to select a quantized symbol as a function of a current quantized complex state of the intermediary signal and a current quantized state of the phase signal, and
• a pulse generator arranged to receive the quantized symbol selected at each oversampling clock period, wherein the pulse generator is adapted to generate the pulse train segment encoded by the received quantized symbol, wherein the generated pulse train segment encodes the information content of the complex input signal in the position and/or width and amplitude of the pulses of the pulse train segment, wherein the pulse generator operates at a second oversampling clock rate.