Transmitter Linearization via Histogram-Based Equalizer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication systems face performance degradation due to nonlinear operation of digital to analog converters (DACs) and power amplifiers (PAs), which existing technologies fail to adequately correct without employing expensive, high-power, and complex high-fidelity components.
Innovation Solution
Incorporating an equalizer with comparators and a processor to determine the transfer function of the transmitter, using comparison count values to modify equalizer parameters, thereby compensating for nonlinear effects in DACs and PAs, and characterizing transmitter operation to achieve linearization without requiring high-speed, high-fidelity components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-fidelity circuits operating at high-speeds are employed to observe and correct transmitter signals, then signal quality and distortion correction are improved, but device complexity, power consumption, and cost increase significantly
Solution Approach 1:
The patent replaces expensive, complex high-fidelity observation circuits with a simple histogramming mechanism that counts signal amplitude occurrences. This disposable-like approach uses basic comparators and counters instead of sophisticated measurement equipment, achieving adequate correction without the complexity and cost of high-performance components
Solution Approach 2:
The patent substitutes complex electronic measurement systems with a statistical histogramming approach. Instead of using high-speed oscilloscopes or spectrum analyzers to observe signals, the system uses a histogramming mechanism that accumulates amplitude distribution data over time, replacing sophisticated measurement mechanics with simpler statistical processing
2Reliability
If high-fidelity circuits are used to correct transmitter distortion, then distortion correction performance is improved, but power consumption increases significantly
Solution Approach 1:
The patent employs low-power histogramming circuitry consisting of simple comparators and counters instead of power-hungry high-fidelity measurement equipment. The histogram accumulation process uses minimal energy while still providing sufficient data for effective distortion correction through transfer function determination
Solution Approach 2:
The system performs histogramming over a period of time to accumulate sufficient amplitude distribution data, then processes this accumulated data to determine the transfer function. This periodic accumulation and processing approach reduces instantaneous power consumption compared to continuous high-speed measurement
3Device complexity
If simple histogramming is used instead of complex measurement systems, then device complexity and cost are reduced, but measurement precision may be compromised
Solution Approach 1:
The patent creates a statistical copy of the transmitter's amplitude distribution through histogramming. Instead of directly measuring and analyzing the complex time-varying signal waveform, the system creates an amplitude distribution histogram that captures the essential characteristics needed for transfer function determination, providing sufficient measurement precision for correction purposes
Solution Approach 2:
The patent transforms the measurement approach from direct time-domain signal analysis to statistical amplitude distribution analysis. By changing the parameter being measured from instantaneous signal values to amplitude occurrence frequencies, the system achieves adequate characterization accuracy with simpler measurement mechanisms
Data Source
AI summary
A transmitter's operation is characterized using components having relatively low cost and low complexity. A device includes comparator(s) that compare a transmitter's analog output to predetermined level(s) to generate count(s) associated with analog output range bin(s). Each of the predetermined levels is associated with a corresponding one of the analog output range bins. A transfer function of the transmitter is generated using the comparison count values associated with the analog output range bin(s). A histogram may be generated from the comparison count values associated with the various analog output range bins. An equalizer is implemented to process data that will be transmitted by the transmitter. The equalizer uses equalizer parameter(s) that are selected based on the characterization of the transmitter (e.g., its transfer function, its histogram, etc.). The equalizer may use default or start up parameters until the transmitter's operation is characterized.