Multi-standard Peak Canceling Circuitry with Pulse Allocator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-standard crest factor reduction (CFR) systems in wireless integrated circuits face inefficiencies due to excessive peak cancellation in scenarios with complementary peaks and unacceptably high error vector magnitude (EVM) degradation when performing peak cancellation on waveforms with different power contributions.
Innovation Solution
The implementation of a peak canceling circuit with a pulse allocator that determines whether the aggregated waveform contains peaks, and if so, generates separate weighting factors to adjust the amount of peak cancellation for each carrier waveform, optimizing EVM and power efficiency by fine-tuning the CFR process based on performance requirements of each standard.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If peak cancellation operations are performed separately on the first and second waveforms prior to summation, then peak cancellation is applied to each waveform individually, but excessive peak cancellation occurs when waveforms have complementary peaks that cancel out with each other
Solution Approach 1:
The patent performs preliminary peak detection on individual waveforms before summation, but delays the actual peak cancellation operation until after summation. The cancellation pulses are generated based on the aggregated waveform's peaks, not the individual waveforms' peaks, thereby avoiding excessive cancellation when peaks are complementary.
2Reliability
If peak cancellation operations are performed on the sum of the first and second waveforms, then peak cancellation is optimized for the aggregated signal, but power is subtracted from waveforms with lower power contribution resulting in high EVM degradation
Solution Approach 1:
The patent applies different peak cancellation strengths to different waveforms based on their individual characteristics and power contributions. The pulse allocator circuit assigns different cancellation pulse amplitudes to each waveform path, allowing stronger cancellation for dominant waveforms and weaker or no cancellation for subordinate waveforms, thereby minimizing EVM degradation while maintaining aggregated waveform performance.
3Adaptability or versatility
If separate peak cancellation is applied to each carrier waveform, then each waveform can be optimized independently, but the system complexity increases with multiple peak detectors and control mechanisms
Solution Approach 1:
The patent merges the peak detection function into a single unified operation performed on the aggregated waveform after summation. Instead of requiring separate peak detectors for each waveform, the system uses one peak detector to identify peaks in the combined signal, then allocates appropriate cancellation pulses to each waveform path based on the detected peak locations and individual waveform characteristics.
Data Source
AI summary
Integrated circuits with wireless communications circuitry having peak cancelation circuitry operable to perform crest factor reduction is provided. The peak cancelation circuitry may receive at least first and second carrier waveforms and may include at least a first canceling pulse generator (CPG), a second CPG, a first peak detector for performing peak detection on the first waveform, a second peak detector for performing peak detection on the second waveform, a third peak detector for performing peak detection on a combined waveform of the first and second waveforms, and a pulse allocator that receives clipping information from the three peak detectors and that controls the amount of peak cancelation that is being performed by the two CPGs. The allocator may determine whether the combined waveform contains any peaks. In response to determining that the combined waveform does not contain any peaks, the CPGs may be configured in bypass mode.