Dynamic Peak Reduction Tone Allocation for OFDM PAPR
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Solution Overview
Problem
Contemporary wireless communication systems employing OFDM face challenges in reducing the high peak-to-average power ratio (PAPR), which limits transmission performance and can cause distortion in power amplifiers.
Innovation Solution
The implementation of a dynamic tone reservation (TR) algorithm that allows for flexible selection of peak reduction tones (PRTs) to reduce PAPR, involving the determination of a set of tones for use as PRTs based on control information and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM is used for wireless transmission, then spectral efficiency and data rate are improved, but peak-to-average power ratio increases causing distortion in power amplifiers
Solution Approach 1:
The patent extracts and isolates the peak power reduction function to dedicated peak reduction tones (PRTs) within the OFDM signal. By separating the PAPR reduction mechanism from the data-carrying tones, the system can apply aggressive peak clipping and filtering on PRTs without distorting the main data signal, thus resolving the contradiction between maintaining high data rates and reducing peak power effects.
Solution Approach 2:
The patent introduces an intermediary signal component carried on PRTs that acts as a mediator to cancel or reduce peak power excursions in the overall OFDM signal. This intermediary peak reduction signal is generated based on the detected peak locations and is superimposed on the data signal, allowing the system to maintain both high data rates and reduced peak-to-average power ratio.
2Reliability
If PAPR reduction techniques are applied, then transmission performance is improved, but signal distortion may occur
Solution Approach 1:
The patent segments the OFDM signal into two distinct parts: data-carrying tones and peak reduction tones (PRTs). By applying different processing functions to each segment, the system can aggressively reduce peaks on PRTs without affecting the integrity of the data signal. This segmentation allows PAPR reduction to be achieved while maintaining signal fidelity and avoiding distortion in the main data transmission.
Solution Approach 2:
The patent applies local quality by treating PRTs differently from data tones. PRTs are specifically designated to carry peak reduction information and can be heavily processed or clipped without affecting overall signal quality. The data-carrying tones maintain their original quality and integrity, while PRTs locally absorb the peak reduction function, thus achieving PAPR reduction without compromising overall transmission performance.
3Reliability
If dynamic PRT selection is implemented, then PAPR reduction effectiveness is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic PRT selection where the positions and number of PRTs are not fixed but adapt based on the detected peak locations in the OFDM signal. This dynamic allocation allows the system to concentrate peak reduction resources exactly where needed, improving PAPR reduction effectiveness. The system dynamically adjusts PRT configuration per OFDM symbol or block, ensuring optimal performance while managing complexity through efficient detection and selection algorithms.
Solution Approach 2:
The patent changes key parameters such as the number of PRTs, their positions, and the clipping threshold dynamically based on signal characteristics and peak locations. By adapting these parameters rather than using fixed values, the system achieves better PAPR reduction effectiveness. The parameter changes are driven by real-time signal analysis, allowing the system to optimize performance for each transmission block while managing complexity through efficient parameter adjustment mechanisms.
Data Source
AI summary
Aspects of the disclosure relate to techniques for peak-to-average power ratio (PAPR) reduction based on a tone reservation (TR) algorithm. For a TR algorithm, a suitable subset of tones from among a full set of tones in a given resource allocation are reserved for use as peak reduction tones (PRT). An apparatus such as a transmission/reception point receives a set of one or more PRT sequences and stores them in memory. The transmission/reception point then determines a set of PRTs based on one or more later-received PRT sequence selection parameters. Other aspects, embodiments, and features are also claimed and described.