Dynamic Crest Factor Reduction in Distributed Communication Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional crest factor reduction techniques in distributed communication systems are static and fail to adapt to changing system parameters, leading to signal distortion and excessive non-linear emissions due to high peak-to-average ratios in electromagnetic signals.
Innovation Solution
A distributed communication system with a system controller that dynamically determines crest factor reduction configuration parameters based on signal and power amplifier parameters, distributing these to nodes for adaptive crest factor reduction, thereby adjusting signal clipping thresholds to optimize signal processing and reduce saturation in power amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional static CFR techniques are used to reduce peak-to-average ratios, then power amplifier saturation is reduced, but signal distortion increases and the system cannot adapt to changing parameters
Solution Approach 1:
The patent implements dynamic CFR by continuously monitoring signal parameters (peak-to-average ratio, clipping threshold violations) and adjusting CFR configuration parameters in real-time. The system transitions from static pre-configured CFR to adaptive CFR that dynamically responds to changing signal conditions, power amplifier operating points, and traffic loads, thereby maintaining optimal performance without excessive distortion.
Solution Approach 2:
The system changes CFR configuration parameters (such as clipping thresholds, reduction factors, and activation conditions) based on monitored signal characteristics and power amplifier operating conditions. By adjusting these parameters dynamically, the system optimizes the balance between preventing saturation and minimizing signal distortion under varying operational scenarios.
2Power
If high crest factor signals are amplified to increase output power, then signal coverage is improved, but intermodulation products and out-of-band emissions increase
Solution Approach 1:
The system applies CFR as a preliminary signal processing step before power amplifier amplification. By pre-reducing the crest factor of the signal through clipping and filtering operations, the signal is prepared in advance to prevent power amplifier saturation, thereby avoiding the generation of intermodulation products and out-of-band emissions during the high-power amplification stage.
3Ease of operation
If static CFR configuration is used to simplify system operation, then implementation is easier, but the system cannot adapt to changing nodes, signals, or system parameters
Solution Approach 1:
The system implements feedback mechanisms where signal parameters (peak-to-average ratio, clipping threshold violations) and power amplifier operating conditions are continuously monitored. This feedback information is used to dynamically adjust CFR configuration parameters, enabling the system to adapt to changing conditions while maintaining automated operation that simplifies deployment across distributed nodes with varying characteristics.
Data Source
AI summary
To provide improvements in crest factor reduction in a distributed communication system, CFR configuration parameters can be determined based on communication signals received from a base station entity and distributed to node(s) of the distributed communication system. CFR engine(s) in the node(s) may perform CFR based on the CFR configuration parameters, and/or may adjust their CFR engine(s) based on signal parameters and/or operating parameters of a power amplifier coupled to a respective CFR engine. Some or all CFR processing may be offloaded from a node and assigned to optical transport card(s) of the system controller based on a processing bandwidth associated with the optical transport card(s).