Envelope Path Pre-distortion for Wideband Transmitter Systems
AssigneeBroadcom Corporation
InventorsDebopriyo Chowdhury, Ali Afsahi
Life of this patent
Estimating the term…
Abstract
A communication device, such as a smart phone, includes an envelope tracking power supply modulator. The envelope tracking power supply modulator receives an envelope tracking reference signal. A baseband controller pre-distorts the envelope tracking reference signal responsive to distortion caused by the envelope tracking power supply modulator. For instance, the pre-distortion may modify the nominal envelope tracking reference signal so that, after the modulator acts on the modified reference signal, the output of the modulator has increased linearity.
Claims20
A device comprising:
- a baseband controller;
- and
- a supply modulator operable to:
- receive an envelope tracking reference signal from the baseband controller;
- generate, according to a linearity characteristic, an envelope tracking power supply signal responsive to the envelope tracking reference signal;
- and
- provide an envelope sense signal that reflects the linearity characteristic;
- where the baseband controller is configured to:
- receive the envelope sense signal;
- and
- pre-distort the envelope tracking reference signal responsive to the linearity characteristic.
A method comprising:
- receiving an envelope sense signal that reflects a linearity characteristic of an envelope tracking power supply modulator;
- and
- pre-distorting an envelope tracking reference signal, from which the envelope sense signal is derived, responsive to the linearity characteristic.
A device comprising:
- a baseband controller comprising:
- a selection output;
- a signal input;
- and
- a radio frequency envelope output;
- an envelope tracking power supply modulator operable to:
- receive an envelope tracking reference signal from the baseband controller on the radio frequency envelope output;
- apply the envelope tracking reference signal to a linear regulator that is characterized by a linearity characteristic to generate a regulated output responsive to the envelope tracking reference signal;
- and
- output an envelope tracking power supply signal and an envelope sense signal responsive to the regulated output;
- a buffer operable to receive the envelope sense signal and comprising a buffer output;
- and
- an analog to digital converter coupled to the buffer output and to the baseband controller,
- where the baseband controller is configured to:
- selectively determine when to receive the envelope sense signal from the analog to digital converter and pre-distort the envelope tracking reference signal to at least partially compensate for the linearity characteristic.
Dependencies are inferred from the claim text.