DIGITAL PREDISTORTION OF A POWER AMPLIFIER FOR SIGNALS COMPRISING WIDELY SPACED CARRIERS
First Claim
1. A predistortion linearized amplifier system for amplifying a communication signal having at least first and second separate signal components, comprising:
- one or more inputs adapted to receive a communication signal, the communication signal having at least first and second separate signal components;
a digital predistorter coupled to the one or more inputs and receiving the first and second separate signal components, the digital predistorter outputting a combined predistorted output signal based on first and second predistortion coefficients applied to the first and second separate signal components and intermodulation distortion products of the first and the second separate signal components;
a digital to analog converter coupled to receive the combined predistorted output signal and provide an analog signal; and
,a power amplifier coupled to the digital to analog converter and amplifying the analog signal to provide an amplified analog signal.
6 Assignments
0 Petitions
Accused Products
Abstract
Digital predistortion (“DPD”) of an RF power amplifier for signals comprising two widely spaced carrier clusters is proposed. The basis waveforms within the DPD are selected to allow for the use of a lower sampling rate. As one example, multi-carrier signals spanning 60 MHz of bandwidth may be linearized using a sample rate of 100 MHz for the DPD module and the observation path, as opposed to a sample rate exceeding 300 MHz (5 times Nyquist) used conventionally. A transmit (Tx) filter is located after the power amplifier to attenuate distortion modes exceeding the sampling rate used.
-
Citations
20 Claims
-
1. A predistortion linearized amplifier system for amplifying a communication signal having at least first and second separate signal components, comprising:
-
one or more inputs adapted to receive a communication signal, the communication signal having at least first and second separate signal components; a digital predistorter coupled to the one or more inputs and receiving the first and second separate signal components, the digital predistorter outputting a combined predistorted output signal based on first and second predistortion coefficients applied to the first and second separate signal components and intermodulation distortion products of the first and the second separate signal components; a digital to analog converter coupled to receive the combined predistorted output signal and provide an analog signal; and
,a power amplifier coupled to the digital to analog converter and amplifying the analog signal to provide an amplified analog signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A predistorter for use in predistortion of a communication signal having at least first and second separate signal components, comprising:
-
a first input adapted for receiving a first separate signal component; a second input adapted for receiving a second separate signal component; a first intermodulation distortion compensation circuit receiving first predistortion coefficients and the first and second separate signal components, the first intermodulation distortion compensation circuit creating a first set of intermodulation distortion products and providing a first predistorted output signal based on the first set of intermodulation distortion products, the first predistortion coefficients, and the first separate signal component; a second intermodulation distortion compensation circuit receiving second predistortion coefficients and the first and second separate signal components, the second intermodulation distortion compensation circuit creating a second set of intermodulation distortion products and providing a second predistorted output signal based on the second set of intermodulation distortion products, the second predistortion coefficients, and the second separate signal component; and
,a combiner circuit which receives and combines the first and second predistorted output signals to provide a combined predistorted output signal. - View Dependent Claims (9, 10, 11)
-
-
12. A method for predistortion linearization of a signal in a communication system, the signal having two separate components, the method comprising:
-
receiving a first input signal component; receiving a second input signal component; receiving first and second predistortion coefficients; providing a first predistorted output signal based on a first set of intermodulation distortion products of the first and second signal components, the first predistortion coefficients, and the first digital input signal; providing a second predistorted output signal based on a second set of intermodulation distortion products of the first and second signal components, the second predistortion coefficients, and the second input signal component; and
,combining the first and second predistorted output signals to provide a combined predistorted output signal. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
-
Specification