Patent ID: 7579922

Claim:
A polar transmitter, comprising: a modulator coupled to receive a digital signal and including: a symbol mapper coupled to receive the digital signal and operable to produce in-phase and quadrature symbols based on the digital signal, wherein the symbol mapper is operable to map data bits within the digital signal to a stream of digital symbols outside of an exclusion region defined around a zero-crossing of a complex plane representing the digital symbols, the stream of digital symbols forming the in-phase and quadrature symbols; and a pulse shaper coupled to receive the in-phase and quadrature symbols and operable to produce in-phase and quadrature signals based on the in-phase and quadrature symbols; a conversion module operable to convert the in-phase and quadrature signals to a variable-envelope modulated signal including an envelope signal and a phase signal; a two-point modulation phase-locked loop including: a first input coupled to receive the phase signal of the variable-envelope modulated signal and coupled to provide the phase signal along a first signal path to produce a first frequency modulation signal, a second input coupled to receive the phase signal and coupled to provide the phase signal along a second signal path to produce a second frequency modulation signal, the first and second frequency modulation signals being produced by differentiation of the phase signal, and a voltage controlled oscillator having a first modulation point coupled to the first signal path to receive the first frequency modulation signal and a second modulation point coupled to the second signal path to receive the second frequency modulation signal, wherein the voltage controlled oscillator is controlled by an aggregate of the first frequency modulation signal and the second frequency modulation signal to up-convert the phase signal from an intermediate frequency (IF) to a radio frequency (RF) to produce an RF signal; and a power amplifier operable to produce a modulated RF signal based on the RF signal and the envelope signal.