Active-Array Power Amplifier Predistortion for ACLR and Spatial Emissions
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Solution Overview
Problem
Multi-antenna wireless communication systems face challenges in reducing spatial emissions, particularly in 5G networks, due to power amplifier nonlinearity, leading to adjacent channel leakage and interference with adjacent frequency systems.
Innovation Solution
The implementation of digital pre-distortion (DPD) and analog pre-distortion techniques to linearize power amplifiers, minimizing radiation patterns in azimuth and elevation directions, and adjusting pre-distortion signals based on power levels to reduce adjacent channel leakage ratio (ACLR) and spatial emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power amplifiers operate at high power levels to meet data demand, then transmission power is improved, but spatial emissions and adjacent channel leakage increase
Solution Approach 1:
The patent applies pre-distortion techniques where distortion compensation is performed before the power amplifier processes the signal. By pre-distorting the input signal to counteract the expected non-linear behavior of the power amplifier, the system achieves linear output characteristics at high power levels without generating excessive spatial emissions or adjacent channel leakage.
Solution Approach 2:
The patent dynamically adjusts pre-distortion parameters based on the operating conditions of the power amplifier. By changing the pre-distortion signal characteristics in response to varying power levels and amplifier states, the system maintains optimal linearity and minimizes harmful emissions across different transmission power conditions.
2Productivity
If power amplifiers are operated to meet 5G data demands, then productivity is improved, but adjacent channel leakage ratio increases causing interference
Solution Approach 1:
The system performs pre-distortion processing before signal transmission to pre-compensate for power amplifier non-linearities. This preliminary action ensures that even when power amplifiers operate at high levels to meet 5G productivity demands, the resulting adjacent channel leakage is minimized, allowing coexistence with adjacent frequency systems.
3Productivity
If multiple antennas are used to enhance communication capacity, then productivity is improved, but spatial emissions and interference with adjacent systems worsen
Solution Approach 1:
The patent applies pre-distortion techniques to each antenna's power amplifier chain before signal transmission. This preliminary compensation ensures that multi-antenna systems can operate at high capacity without generating excessive spatial emissions that would interfere with adjacent frequency systems, enabling both high productivity and spectral coexistence.
Data Source
AI summary
Facilitating the reduction and/or mitigation of spatial emissions in a multi antenna wireless communications system is provided herein. A system can comprise a memory that stores executable instructions that, when executed by a processor, facilitate performance of operations that can comprise applying a first signal linearization to a first output signal of a first power amplifier based on a determination that an adjacent channel leakage ratio of the first output signal of the first power amplifier fails to satisfy a defined output value. The operations can also comprise applying a second signal linearization to a group of output signals of a group of power amplifiers for a defined azimuth direction associated with channel frequencies of the group of output signals and applying a third signal linearization to the group of output signals for a defined elevation direction associated with the channel frequencies of the group of output signals.