Multi-Carrier Communication DPD Feedback for Distortion Compensation
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Solution Overview
Problem
Existing communication systems face challenges with inter-carrier inter-modulation distortion (IMD) due to carriers passing through a common power amplifier, leading to increased hardware costs and power consumption, and inaccurate nonlinear distortion compensation.
Innovation Solution
A communication method where the receiving device determines a digital pre-distortion (DPD) coefficient based on the received carrier signal, which is fed back to the sending device for accurate nonlinear distortion compensation, eliminating the need for an independent feedback circuit in the sending device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If carriers in a plurality of frequency bands pass through a common power amplifier to reduce device costs, then device costs are reduced, but inter-carrier inter-modulation distortion occurs and nonlinear distortion compensation accuracy is insufficient
Solution Approach 1:
The patent implements a feedback mechanism where the receiving device measures the transmitted carrier signal, calculates DPD coefficients based on the measured signal characteristics, and feeds back these coefficients to the sending device. This closed-loop feedback enables accurate nonlinear distortion compensation without requiring complex hardware at the transmitting end, thus maintaining low device costs while improving compensation accuracy.
2Measurement precision
If an independent feedback circuit is added to the sending device to calculate DPD coefficients, then nonlinear distortion compensation accuracy is improved, but hardware costs and power consumption increase
Solution Approach 1:
The patent inverts the traditional DPD coefficient calculation approach by moving the calculation function from the sending device to the receiving device. Instead of the sending device measuring its own transmitted signal and calculating coefficients, the receiving device measures the received signal (which includes channel effects) and calculates coefficients that are then fed back. This inversion eliminates the need for independent feedback circuits at the sending device, reducing hardware complexity and power consumption.
Solution Approach 2:
The patent uses the communication channel itself as an intermediary to transfer the DPD coefficient information. The receiving device calculates coefficients based on the received signal and feeds them back through the same communication channel used for data transmission, eliminating the need for separate dedicated feedback hardware circuits at the sending device.
3Device complexity
If local feedback channel is used to calculate DPD coefficient, then device complexity is reduced, but compensation accuracy for entire transmitting and receiving link is insufficient
Solution Approach 1:
The patent implements a system-level feedback mechanism where the receiving device, which has actual knowledge of the received signal quality and channel conditions, calculates DPD coefficients and feeds them back to the sending device. This ensures that the compensation coefficients accurately reflect the actual transmission link characteristics, including both transmitting and receiving components, thereby improving overall link compensation accuracy while keeping device complexity low.
Data Source
AI summary
A communication method and apparatus are provided to reduce device costs and power consumption and improve accuracy of nonlinear distortion of receiving and transmitting of a communication system. A sending device sends a first carrier signal to a receiving device and obtains a digital pre-distortion DPD coefficient fed back by the receiving device, where the DPD coefficient is determined by the receiving device based on the received first carrier signal. The sending device performs, based on the DPD coefficient, digital pre-distortion processing on a multi-carrier signal to generate a nonlinear pre-distortion signal and generates a second carrier signal based on the nonlinear pre-distortion signal, where the signal to be sent is loaded with a baseband signal, and transmits the second carrier signal to the receiving device.