Millimeter-Wave Full-Duplex AGC Using Dual ADC Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Full-duplex wireless communications in millimeter wave systems face significant self-interference issues, causing signals to exceed the dynamic range of analog-to-digital converters and resulting in signal clipping and distortion.
Innovation Solution
Implementing a dual analog-to-digital conversion (ADC) approach with signal attenuation and amplification, where a second ADC determines if the signal should be attenuated before processing by the first ADC, and RF sensors adjust gain states of low-noise amplifiers to keep signals within the dynamic range, thereby reducing self-interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex communications are implemented to increase signaling throughput, then communication efficiency is improved, but self-interference increases causing signals to exceed ADC dynamic range
Solution Approach 1:
The patent divides the signal processing into two separate ADC paths: a first ADC for normal signal conversion and a second ADC for monitoring signal levels that would exceed the first ADC's dynamic range. This segmentation allows the system to handle both strong self-interference and weak desired signals simultaneously, resolving the contradiction between full-duplex throughput and self-interference management.
Solution Approach 2:
The patent introduces an intermediary mechanism (the second ADC and associated monitoring circuitry) that detects when signals exceed the dynamic range of the first ADC. This intermediary enables proactive attenuation before saturation occurs, allowing full-duplex operation to proceed without signal clipping while maintaining communication efficiency.
2Reliability
If ADC dynamic range is increased to accommodate self-interference, then signal clipping is reduced, but device complexity and cost increase
Solution Approach 1:
Instead of using a single high-dynamic-range ADC, the patent segments the conversion function into two standard ADCs: one for normal operation and another for monitoring extreme signal levels. This approach achieves the same reliability benefit as a high-dynamic-range ADC without requiring expensive, complex hardware specifications.
Solution Approach 2:
The patent creates a redundant signal path with a second ADC that copies the input signal for monitoring purposes. This copy enables the system to detect and respond to dynamic range violations without requiring the main ADC to handle extreme conditions, thereby maintaining signal quality while using standard, lower-complexity ADC components.
3Reliability
If signal attenuation is applied to prevent saturation, then ADC dynamic range is maintained, but signal strength is reduced requiring amplification
Solution Approach 1:
The patent applies attenuation in advance, before the signal enters the first ADC, based on predictions from the second ADC about upcoming signal levels. This preliminary action prevents saturation before it occurs, and the subsequent amplification restores signal strength, ensuring reliable ADC operation without permanent signal degradation.
Solution Approach 2:
The patent implements a feedback loop where the second ADC continuously monitors input signal levels and provides information to control the attenuation and amplification of the first ADC path. This feedback mechanism dynamically adjusts signal strength to maintain optimal operation within the ADC's dynamic range while preserving communication reliability.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. In some cases, a device may perform a first analog to digital conversion (ADC) to generate a first set of samples of a wireless signal, and may attenuate the signal according to a dynamic range. The device may then perform a second ADC on the attenuated signal to generate a second set of samples, amplify the second set of samples, output whichever set of samples is greater. In some other cases, the second ADC may determine to attenuate the wireless signal based on an input power, amplify the signal, and output the amplified samples. In some other cases, the wireless device may determine an estimated input power of the wireless signal at a number of antenna elements. The device may then determine an adjustment to gain states of low-noise amplifiers (LNA) associated with each of the number of antenna elements.