PMIC Voltage Switching for OFDM Symbol Power Transitions
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Solution Overview
Problem
The challenge of efficiently managing power transitions in a power management integrated circuit (PMIC) for 5G-NR systems, where inter-symbol power variations require rapid voltage adjustments within OFDM symbols to prevent RF signal distortion, is not adequately addressed by existing technologies.
Innovation Solution
A PMIC that dynamically switches modulated voltages between time intervals using first and second voltage transition schemes, allowing for timely adjustments with a switching interval of less than 20 nanoseconds, thereby reducing potential power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the PMIC uses a conventional voltage switching approach, then the circuit structure remains simple, but the voltage transition time exceeds the cyclic prefix duration causing RF signal distortion
Solution Approach 1:
The voltage transition process is segmented into multiple phases: a first voltage level is applied during the data portion of the OFDM symbol, then switched to a second voltage level during the cyclic prefix portion. This segmentation allows the PMIC to achieve rapid voltage transitions aligned with the OFDM symbol structure, ensuring the transition completes within the cyclic prefix guard interval without distorting the RF signal.
Solution Approach 2:
The PMIC implements dynamic voltage switching capability that adapts to time-variant power requirements of 5G-NR systems. The voltage processing circuit dynamically adjusts the voltage level supplied to the power amplifier circuit based on the OFDM symbol timing, enabling rapid transitions between different voltage levels to match the modulated power requirements of each OFDM symbol.
2Productivity
If the PMIC increases modulation bandwidth to exceed 200 MHz, then data rates improve, but OFDM symbol duration decreases making voltage switching more challenging
Solution Approach 1:
The PMIC performs preliminary voltage switching action during the cyclic prefix portion of the OFDM symbol, before the actual data transmission begins. By completing the voltage transition in advance during the guard interval, the system supports higher modulation bandwidths and shorter OFDM symbol durations without compromising the integrity of the data portion, enabling 5G-NR data rates to exceed 200 MHz.
3Reliability
If the PMIC fails to switch voltage within the cyclic prefix, then circuit operation remains stable, but RF signal distortion occurs due to amplitude clipping
Solution Approach 1:
The PMIC incorporates feedback mechanisms that monitor the voltage switching process and the state of the power amplifier circuit. This feedback enables the control circuit to adjust the voltage switching timing and duration to ensure the transition completes within the cyclic prefix guard interval, preventing RF signal distortion while maintaining reliable operation across varying 5G-NR transmission conditions.
Data Source
AI summary
Voltage switching in a power management integrated circuit (PMIC) is provided. The PMIC is required to increase or decrease a modulated voltage from a present voltage level in a present one of multiple time intervals to a future voltage level in an upcoming one of the time intervals with a very short switching interval. Herein, the PMIC determines whether to change the modulated voltage based on a first voltage transition scheme or a second voltage transition scheme, and toggle between the first voltage transition scheme and the second voltage transition scheme dynamically from one time interval to another. By employing the first voltage transition scheme or the second voltage transition scheme, the PMIC can switch the modulated voltage in a timely manner. Further, by opportunistically employing the first voltage transition scheme whenever possible, the PMIC can also help reduce potential power loss associated with switching the modulated voltage.