Rf transmitter, integrated circuit device, wireless communication unit and method therefor

An integrated circuit device comprising:

• at least one digital signal processing module comprising at least one digital pre-distortion component arranged to:
• receive at least one complex input signal comprising information to be transmitted over a radio frequency (RF) interface,
• perform two-dimensional non-uniform mapping of the at least one received complex input signal to a first, in-phase digital pre-distortion control word and at least one further, quadrature digital pre-distortion control word, and
• an output port arranged to output the in-phase and quadrature digital pre-distortion control words to at least one power amplifier module comprising a first, in-phase, array of switch-mode power cells and at least one further, quadrature, array of switch-mode power cells, wherein the two-dimensional non-uniform mapping comprises a pre-distortion profile that is at least partly based on an input/output relationship for the at least one power amplifier module, such that an analogue RF signal for transmission is generated based at least partly on the in-phase and quadrature digital pre-distortion control words.

A wireless communication unit comprising a radio frequency (RF) transmitter comprising:

• at least one digital signal processing module comprising at least one digital pre-distortion component arranged to:
• receive at least one complex input signal comprising information to be transmitted over an RF interface,
• perform two-dimensional non-uniform mapping of the at least one received complex input signal to a first, in-phase digital control pre-distortion word and a further quadrature digital pre-distortion control word, and
• output the in-phase and quadrature digital pre-distortion control words;
• and
• at least one power amplifier module comprising a first, in-phase, array of switch-mode power cells and at least one further, quadrature, array of switch-mode power cells, wherein the two-dimensional non-uniform mapping comprises a pre-distortion profile that is at least partly based on an input/output relationship for the at least one power amplifier module, the at least one power amplifier module being arranged to:
• receive the in-phase and quadrature digital pre-distortion control words output by the at least one digital signal processing module, and
• generate an analogue RF signal for transmission over the RF interface based at least partly on the in-phase and quadrature digital pre-distortion control words.

A method of generating a radio frequency signal for transmission over a radio frequency (RF) interface, the method comprising:

• receiving at least one complex input signal comprising information to be transmitted over the RF interface;
• performing two-dimensional non-uniform mapping of the at least one received complex input signal to a first, in-phase, digital pre-distortion control word and at least one further, quadrature, digital pre-distortion control word;
• providing the in-phase and quadrature digital pre-distortion control words to at least one power amplifier module comprising a first, in-phase, array of switch-mode power cells and at least one further, quadrature, array of switch-mode power cells;
• wherein the two-dimensional non-uniform mapping comprises a pre-distortion profile that is at least partly based on an input/output relationship for the at least one power amplifier module, and
• generating an analogue RF signal for transmission over an RF interface based at least partly on the in-phase and quadrature digital control words.