Multiplexed Reference Signals for PA Nonlinearity Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power amplifiers in wireless communication devices generate nonlinear distortions, leading to in-band and out-of-band interference, which degrade reception performance and reduce network quality, and existing methods to mitigate these distortions result in reduced PA efficiency and power inefficiency.
Innovation Solution
Multiplexing low peak-to-average power ratio (PAPR) demodulation reference signals (DM-RS) with high PAPR RS within a single slot to estimate power amplifier nonlinearity, using a low PAPR DM-RS for channel estimation and a high PAPR RS to mitigate nonlinearity distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power amplifier operates at high power to improve transmission quality, then transmission quality improves, but nonlinear distortions increase causing in-band and out-of-band interference
Solution Approach 1:
The patent segments the reference signal transmission into multiple slots, with each slot containing a reference signal transmitted at a different power level. This allows the receiver to obtain channel state information from multiple power conditions, enabling accurate PA nonlinearity estimation without requiring the PA to operate at excessively high power levels that would cause harmful distortions.
Solution Approach 2:
The patent uses reference signals transmitted at known power levels as a preliminary step to estimate PA nonlinearity characteristics. By pre-transmitting reference signals with known properties and receiving their distorted versions, the system can calculate nonlinearity parameters before actual data transmission occurs, allowing for compensation during normal operation.
2Object-generated harmful factors
If power amplifier operates in linear region to reduce nonlinear distortions, then in-band and out-of-band interference reduce, but PA efficiency decreases
Solution Approach 1:
The system performs PA nonlinearity estimation using reference signals transmitted at known power levels before actual data transmission. This preliminary characterization allows the receiver to compensate for nonlinearities during normal operation, enabling the PA to operate at higher power levels with better efficiency while maintaining low interference through digital pre-distortion or equalization techniques.
Solution Approach 2:
The patent implements a feedback mechanism where the receiver measures the distorted reference signals, calculates PA nonlinearity parameters, and uses this information to compensate for distortions during data transmission. This feedback loop allows the system to operate the PA at optimal power levels while maintaining linear performance through digital correction.
3Measurement precision
If reference signal is transmitted at high power to accurately estimate PA nonlinearity, then nonlinearity estimation accuracy improves, but in-band and out-of-band interference increase
Solution Approach 1:
The patent divides the reference signal transmission into multiple time slots, with each slot containing a reference signal at a different power level. This segmentation allows the receiver to collect measurements across multiple power conditions, improving estimation accuracy through averaging and reducing the impact of any single high-power distortion event.
Solution Approach 2:
The patent transmits reference signals at multiple power levels, including some that exceed the minimum required for accurate measurement. This excessive action provides redundant measurement data that improves the robustness and accuracy of PA nonlinearity estimation, allowing the system to filter out outliers and use only the necessary portion of the data for final calculations.
Data Source
AI summary
A method for wireless communication by a user equipment (UE) includes transmitting, to a network node, a first message indicating a capability of the UE to transmit a multiplexed low peak-to-average power ratio (PAPR) demodulation reference signal (DM-RS) and a high PAPR reference signal (RS) within a single slot. The method also includes multiplexing, associated with the capability, the low PAPR DM-RS with the high PAPR RS within the single slot. The method further includes transmitting, to the network node, the multiplexed low PAPR DM-RS and high PAPR RS within the single slot.