Multi-Phase CFR Circuit for High-Rate OFDM PAPR Reduction
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Solution Overview
Problem
Existing CFR methods for reducing PAPR in OFDM systems suffer from structural redundancy, low processing speed, and high resource overhead, despite achieving accurate peak cancellation.
Innovation Solution
A high-precision multi-phase CFR system employing a single-stage structure that utilizes multi-phase structural processing, including a main circuit, branch circuit, and adder/subtractor module, with interpolation, maximum magnitude selection, peak screening, and multi-phase CPG coefficients to generate a peak-clipped signal at a high rate while reducing redundancy and resource consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multi-stage fractional delay CFR cascade is used to achieve high-rate peak cancellation, then peak cancellation accuracy is improved, but processing speed decreases and resource overhead increases
Solution Approach 1:
The patent segments the peak cancellation process into multiple phases within a single stage. Instead of using multiple cascaded stages with fractional delays, the invention divides the cancellation operation into several phases that operate simultaneously or sequentially within one stage, achieving high-rate processing without the cumulative overhead of multiple stages.
Solution Approach 2:
The patent transitions from a time-domain multi-stage approach to a phase-domain single-stage approach. By introducing the phase dimension and operating in the frequency domain with phase rotations, the system achieves high-rate peak cancellation without requiring multiple time-domain stages with fractional delays.
2Measurement precision
If multi-stage fractional delay CFR cascade is used to achieve high-rate peak cancellation, then peak cancellation accuracy is improved, but structural redundancy increases
Solution Approach 1:
The patent segments the peak cancellation process into multiple phases within a single stage. Instead of using multiple cascaded stages with fractional delays, the invention divides the cancellation operation into several phases that operate simultaneously or sequentially within one stage, achieving high-rate processing without the cumulative overhead of multiple stages.
Solution Approach 2:
The patent merges multiple fractional delay operations into a single phase rotation operation. By combining the functionality of multiple stages into one unified phase-based cancellation mechanism, the system eliminates structural redundancy while maintaining cancellation accuracy.
3Measurement precision
If limiting is performed directly to reduce PAPR, then PAPR reduction is achieved, but spectrum leakage and EVM degradation occur
Solution Approach 1:
The patent introduces phase rotation as an intermediary mechanism between the original signal and the limiting operation. By rotating the phase of frequency domain symbols before limiting and then compensating after limiting, the system reduces PAPR while minimizing spectrum leakage and EVM degradation caused by direct limiting.
Solution Approach 2:
The patent performs preliminary phase rotation on frequency domain symbols before the limiting operation. This preliminary action prepares the signal in a way that allows subsequent limiting to achieve PAPR reduction with minimal harmful effects, and the inverse rotation after limiting further compensates for any introduced distortion.
Data Source
AI summary
This application discloses a high-precision multi-phase CFR system and method and use. This application relates to the technical field of PAPR reduction. The CFR system is a single-stage multi-phase structure, which is used for an input signal to perform peak searching and phase recording at a high rate, and to perform peak screening, peak allocation and peak cancellation at a single rate; in the cancellation signal generation, the peak noise after the peak screening is pulse shaped and compensated for the recorded phases at the high rate by multi-phase CPG coefficients; and according to the peak allocation, multiple CPG pulse signals are combined to obtain a final cancellation signal; then a delayed original signal and the final cancellation signal are subtracted to obtain a low-PAPR signal for output.