Multi-Antenna Beamforming Calibration Through Internal Tx-Rx Paths
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Solution Overview
Problem
Existing beamforming calibration methods for multi-antenna transceivers face high complexity in hardware and software requirements, dependency on radio channels, and significant signaling overhead, especially when scaling with increasing antenna elements.
Innovation Solution
A method and apparatus for beamforming calibration that involves feeding an analog signal from the transmitter path to the receiver path within each transceiver chain to determine a beamforming calibration factor, using digital calibration signals that invert and normalize the analog signal, allowing for simultaneous calibration of all transceiver chains without requiring additional hardware or over-the-air signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If internal calibration network approaches are used, then beamforming calibration can be achieved, but hardware and software complexity increases significantly
Solution Approach 1:
The patent extracts the calibration function from complex internal calibration networks and implements it using simple connection circuitry that feeds analog signals between transmitter and receiver paths. This removes the need for dedicated calibration hardware while maintaining calibration functionality through the existing transceiver chain infrastructure.
Solution Approach 2:
The connection circuitry serves multiple functions: it enables calibration signaling between transmitter and receiver paths while utilizing existing analog signal paths. The same circuitry that handles normal communication signals is repurposed for calibration, eliminating the need for separate dedicated calibration hardware.
2Reliability
If over-the air signaling approaches are used, then beamforming calibration can be performed, but signaling overhead and radio channel dependency increase
Solution Approach 1:
The patent extracts the calibration process from over-the-air signaling and performs it internally within the transceiver using connection circuitry. This removes the dependency on radio channels for calibration while reducing signaling overhead to minimal digital control signals that trigger and manage the calibration process.
3Measurement precision
If traditional calibration methods are used, then calibration accuracy can be maintained, but scalability with increasing antenna elements deteriorates
Solution Approach 1:
The patent segments the calibration process into independent per-antenna-element operations. Each antenna element's transceiver chain is calibrated independently by feeding signals through its own connection circuitry, allowing linear scaling with the number of elements rather than exponential scaling required by traditional calibration networks.
Data Source
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AI summary
A method of beamforming calibration is disclosed for a multi-antenna transceiver configured to communicate with one or more other transceivers. The multi-antenna transceiver has a plurality of transceiver chains connectable to respective antenna elements of the multi-antenna transceiver. Each transceiver chain comprises a transmitter path and a receiver path. The method comprises (for each transceiver chain) feeding an analog signal from the transmitter path to the receiver path via connection circuitry between the transmitter path and the receiver path to provide a digital calibration signal, and determining a beamforming calibration factor for the transceiver chain based on the digital calibration signal. Corresponding apparatus, multi-antenna transceiver, wireless communication node, and computer program product are also disclosed.