TX RFIC Phase Alignment Signal Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MIMO transceivers face challenges in achieving precise phase alignment between multiple RX and TX signal paths, which is essential for efficient communication, especially in smaller arrays where additional component costs and size become significant due to the need for dedicated calibration transmitters.
Innovation Solution
A TX signal path circuit is configured to generate an RX phase alignment signal, utilizing a digital up-conversion block, DAC, and RF up-conversion block, with separate NCOs and IQ-DIV2 circuits for TX and RX modes, allowing the TX signal path to produce alignment signals without disturbing its normal operation, and employing a feedback LO for RX phase alignment without affecting the TX LO circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated calibration transmitter is added to achieve RX phase alignment, then phase alignment accuracy is improved, but device complexity and size increase
Solution Approach 1:
The TX signal path circuit is configured to perform dual functions: normal TX signal generation and RX phase alignment signal generation. By using the existing TX circuitry for calibration purposes, the patent eliminates the need for a separate dedicated calibration transmitter, thereby maintaining phase alignment accuracy while reducing device complexity and size.
Solution Approach 2:
The TX signal path circuit serves itself by generating RX phase alignment signals using its own internal components (NCO, IQ-DIV2 circuit, feedback LO) without requiring external calibration equipment. This self-service capability allows the system to perform self-calibration, improving phase alignment accuracy without adding external complexity.
2Adaptability or versatility
If separate RX RFICs are used for each RX signal path, then integration flexibility is improved, but manufacturing cost and size increase
Solution Approach 1:
The patent combines multiple RX signal paths onto a single RFIC chip, reducing the total number of discrete components. By integrating the RX signal path circuits along with the TX signal path circuit on one chip, the system maintains flexibility for different MIMO array configurations while reducing manufacturing costs and overall device size.
Solution Approach 2:
The single RFIC is designed to handle multiple functions including TX signal generation, RX signal reception, and phase alignment calibration across multiple signal paths. This multi-functional integration allows the system to support flexible MIMO array sizes without requiring separate dedicated RFICs for each function.
3Measurement precision
If board level calibration is performed to achieve phase alignment, then alignment accuracy is improved, but calibration time and complexity increase
Solution Approach 1:
The system performs automatic phase alignment calibration during the factory manufacturing process using the integrated TX signal path circuit to generate alignment signals. By completing the calibration action beforehand during production, the patent achieves high phase alignment accuracy while eliminating or minimizing the need for time-consuming field calibration procedures.
Solution Approach 2:
The integrated calibration capabilities allow the system to perform automatic self-calibration without requiring external board-level calibration equipment or manual intervention. The TX signal path circuit generates the necessary alignment signals and the system automatically adjusts phase parameters, reducing both calibration time and operational complexity.
Data Source
AI summary
A transmit (TX) signal path circuit in a multiple-input, multiple-output (MIMO) transceiver responsive to a digital front end (DFE) for generating receive (RX) path phase alignment signals is disclosed. A digital up-conversion block uses a first numerically-controlled oscillator (NCO) for generating digital intermediate frequency (IF) signals for ordinary TX signal generation, and a different, second NCO for generating digital IF signals for RX phase alignment signal generation. An RF up-conversion block uses a TX local oscillator (LO) for generating analog RF signals for ordinary TX signal generation, and a different feedback (FB) LO for generating analog RF signals for RX phase alignment signal generation. Thus, phase alignment of the circuitry used for ordinary TX signal generation is left undisturbed by RX phase alignment signal generation.