Time Domain Calibration for Antenna Array Phase Impairments
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Solution Overview
Problem
Antenna arrays in wireless communication systems face challenges in phase distortion compensation, leading to reduced signal quality and increased power consumption, with existing calibration methods disrupting normal traffic signals and failing to meet rapid phase variation requirements.
Innovation Solution
A time domain calibration method using normal outbound traffic signals to estimate and compensate for phase impairments in transmit paths, without injecting special calibration signals, allowing for continuous calibration and maintaining multi-standard compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If special calibration signals are injected into the transmit path for antenna array calibration, then phase distortion compensation is achieved, but normal outbound traffic signals are interrupted and degraded, negatively impacting network capacity and data throughput
Solution Approach 1:
The system uses the outbound traffic signals themselves to perform calibration by capturing reference signals from the traffic flow, estimating impairments, and applying compensation. This self-service approach eliminates the need for external calibration signals while maintaining both calibration accuracy and continuous traffic flow.
Solution Approach 2:
The outbound traffic signals serve dual purposes: they are both the data to be transmitted and the reference signals for calibration. By making the traffic signals multi-functional, the system simultaneously achieves communication and calibration without requiring separate calibration signals that would disrupt normal operations.
2Reliability
If transmission power is increased to compensate for phase distortions, then signal reception and decoding accuracy is improved, but system power allocation for other wireless devices is reduced and signal quality for other devices deteriorates due to interference
Solution Approach 1:
The system performs impairment estimation and phase compensation in advance before the signal is transmitted through the antenna array. By correcting phase distortions preliminarily in the digital baseband domain, the system ensures accurate signal reception without needing to increase transmission power, thereby avoiding interference to other devices.
3Measurement precision
If conventional calibration methods are used, then phase distortion compensation is achieved, but the complexity and processing requirements prevent meeting rapid phase variation correction requirements
Solution Approach 1:
The system changes the domain of calibration from frequency domain to time domain, and uses lightweight impairment estimation techniques that track phase variations in real-time. This parameter change enables the system to meet rapid phase variation correction requirements with reduced computational complexity compared to conventional methods.
4Measurement precision
If special calibration signals are used for antenna array calibration, then phase impairment estimation is possible, but standards compliance and regulatory requirements are violated due to variety of base station configurations
Solution Approach 1:
The system uses its own outbound traffic signals for calibration purposes, making it independent of external calibration signals. This self-service approach ensures compatibility across all base station configurations and standards, as the method works with any normal traffic signal without requiring special calibration signal injection that may violate regulatory requirements.
Data Source
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AI summary
A method and system for time domain calibration to compensate for signal phase impairment in transmit paths in a transmitter configured to drive an antenna array are disclosed. According to one aspect, a base station is configured to compensate for signal impairment in transmit paths feeding an array of antenna elements in which the compensation is performed in the time domain. The base station includes a combiner configured to combine signals output from the transmit paths to form a feedback signal. An impairment estimator is configured to receive the feedback signal and outbound traffic signals and to determine a phase compensation value for each impairment path. A multiplier is provided for each transmit path, the multipliers configured to multiply the outbound traffic signals by respective phase compensation values.