DPD Calibration Signal Power Matching for Amplifier Memory Effects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio communication systems face challenges in accurately calibrating transmission systems due to non-linear distortion and memory effects in amplifiers, which affect the accuracy of digital pre-distortion (DPD) processing.
Innovation Solution
A signal processing apparatus and method that regulate and compensate input and calibration signals to reduce power differences, employing digital pre-distortion to mitigate non-linear distortion and memory effects in amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DPD is applied to suppress memory effect in DL signal, then non-linear distortion of amplifier is reduced, but memory effect distortion remains in DL calibration signal affecting calibration accuracy
Solution Approach 1:
The patent changes the power parameter of the calibration signal to match the power level of the input signal. By regulating the calibration signal's power through the same amplification path and DPD processing as the input signal, the calibration signal experiences identical non-linear distortion and memory effects, enabling accurate calibration that accounts for these distortions.
2Measurement precision
If DL calibration signal has different power level from input signal, then calibration can be performed, but non-linear distortion and memory effect cause inaccurate calibration results
Solution Approach 1:
The patent equalizes the power parameter between calibration signal and input signal by processing the calibration signal through the same amplification and DPD stages. This ensures both signals experience identical non-linear distortion and memory effects, allowing accurate measurement and compensation of these effects during calibration.
Solution Approach 2:
The patent uses feedback by measuring the actual output of the amplifier for both input signal and calibration signal, then using these measurements to determine accurate calibration parameters that account for the amplifier's non-linear distortion and memory effects.
Data Source
AI summary
A signal processing apparatus according to the present disclose includes: a regulation unit configured to regulate one or both of an input signal and a calibration signal for performing calibration of transmission systems so that a difference between signal power of the input signal and signal power of the calibration signal is reduced; a compensation unit configured to perform distortion compensation for the input signal and the calibration signal; an amplifier configured to amplify the input signal and the calibration signal; and an output unit configured to output the input signal and the calibration signal that have been regulated by the regulation unit to the amplifier. Thus, there are provided the signal processing apparatus, a radio communication apparatus, a signal processing method, and a program that reduce non-linear distortion of an amplifier and distortion caused by a memory effect of the amplifier in the calibration signal.