Method and apparatus for reduction of distortion in a transmitter

A communication device having a transmitter that comprises:

• a main signal path that receives an input signal, samples the input signal to produce an attenuated input signal, conveys the attenuated input signal to a feed forward correction circuit, amplifies the input signal to produce an amplified signal that comprises a distortion component, samples the amplified signal to produce an attenuated amplified signal, and conveys the attenuated amplified signal to the feed forward correction circuit;
• a feed forward correction circuit coupled to main signal path that receives the attenuated input signal and the attenuated amplified signal from the main signal path, produces an error signal based on the attenuated input signal and the attenuated amplified signal, amplifies the error signal to produce an amplified error signal that comprises an error component and a distortion component, samples the error signal to produce an attenuated error signal, and conveys the attenuated error signal to a control circuit;
• a control circuit coupled to each of the main signal path and the feed forward correction circuit that receives the attenuated error signal from the feed forward correction circuit, produces a control signal based the attenuated error signal, and conveys the control signal to the main signal path;
• and
• wherein, based on the control signal, the main signal path adjusts an amplitude and a phase of the input signal in order to control an energy of a peak power of the error signal and reduce the distortion component of the amplified error signal.

A method for reducing distortion in a transmitter having a feed forward amplifier, wherein the feed forward amplifier amplifies an input signal to produce an amplified signal, the method comprising steps of:

• sampling the input signal to produce an attenuated input signal;
• sampling the amplified signal to produce an attenuated amplified signal;
• combining the attenuated input signal with the attenuated amplified signal to produce an error signal;
• producing a control signal based on the error signal, wherein the control signal is capable of controlling an energy of the peak power of the error signal;
• and
• wherein the error signal is amplified to produce an amplified error signal that comprises an error component and a distortion component and wherein, by controlling an energy of the peak power of the error signal, the distortion component of the amplified error signal can be minimized by controlling an energy of the peak power of the error signal.

A method for reducing distortion in a transmitter having a feed forward amplifier comprising steps of:

• receiving an input signal;
• amplifying the input signal to produce an amplified signal;
• determining an error signal based on the input signal and the amplified signal;
• amplifying the error signal to produce an amplified error signal, wherein the amplified error signal comprises an error component and a distortion component;
• and
• producing a control signal based on the distortion component of the amplified error signal, wherein the control signal is capable of reducing distortion in the transmitter.