DPD Calibration via Port-Based Training in Beamforming Radios
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Solution Overview
Problem
Current wireless communication systems, particularly 5G NR, face challenges in efficiently performing digital pre-distortion (DPD) training without interfering with other devices, especially in multi-antenna and millimeter wave environments where beamforming and over-the-air coupling complicate DPD calibration.
Innovation Solution
The method involves using uplink and downlink grants to transmit and receive DPD training signals on specific ports, allowing for online DPD training by configuring one layer at a time, thereby avoiding interference with other transmissions and enabling accurate determination of power amplifier responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If DPD training signals are transmitted using existing uplink or downlink resources, then DPD calibration can be performed, but interference with other devices and transmissions occurs
Solution Approach 1:
The patent extracts DPD training signals from shared uplink/downlink resources and assigns them to dedicated physical channels (DPD-UL CH and DPD-DL CH). This separation removes the harmful interference effect while preserving the measurement precision needed for DPD calibration.
Solution Approach 2:
The patent introduces dedicated physical channels as intermediaries between the DPD training functionality and the existing resource allocation system. These dedicated channels act as mediators that enable DPD calibration without directly competing with other transmissions for resources.
2Measurement precision
If DPD training is performed in multi-antenna and millimeter wave environments with beamforming, then DPD calibration can be achieved, but system complexity increases due to over-the-air coupling
Solution Approach 1:
The patent segments the DPD calibration process by port, allowing one port to be configured for transmission while another port receives the training signal. This segmentation simplifies the multi-antenna calibration process by isolating individual port interactions and reducing the complexity of managing over-the-air coupling in beamforming environments.
3Object-affected harmful factors
If dedicated DPD training resources are allocated, then interference with other transmissions is avoided, but system resource overhead increases
Solution Approach 1:
The patent makes existing physical uplink and downlink channels multi-functional by enabling them to carry both traditional data/control traffic and DPD training signals. This universality allows the system to avoid dedicated DPD resources while still preventing interference, as the same channels serve multiple purposes without requiring additional resource allocation.
Data Source
AI summary
Methods, apparatuses, and computer-readable medium for DPD are provided. An example method may include receiving, from a base station, an uplink grant associated with one or more resources. The example method may further include transmitting, to the UE via the one or more resources, a DPD training signal at a first port of a plurality of ports. The example method may further include receiving, at a second port of the plurality of ports, the DPD training signal.