RIS Hierarchical Modulation for Auxiliary Data Without SNR Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The transmission of auxiliary data using Reconfigurable Intelligent Surfaces (RIS) degrades user data performance due to spatial correlation between RIS elements, especially when the auxiliary data is transmitted at the same rate as user data.
Innovation Solution
Implement hierarchical transmission by decoupling the BER performance of user signals from auxiliary signals, transmitting auxiliary data at a lower rate than user symbols, and using phase and amplitude shifts to minimize SNR degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the RIS array is partitioned into tiles and auxiliary data is transmitted by activating tile patterns, then auxiliary data transmission is enabled, but spatial correlation between RIS elements causes high sensitivity and degraded transmission reliability
Solution Approach 1:
The patent divides the RIS array into multiple independently controllable tiles, where each tile can be activated or deactivated to represent auxiliary data bits. This segmentation enables auxiliary data transmission through spatial patterns while managing the spatial correlation issue by treating each tile as a distinct unit.
Solution Approach 2:
The patent applies different activation states to different local regions (tiles) of the RIS array. By controlling which tiles are activated rather than uniformly controlling all elements, the system encodes auxiliary data in the spatial distribution pattern, thereby enabling information transmission while accounting for spatial correlation effects.
2Reliability
If all RIS elements are simultaneously activated to transmit auxiliary data, then transmission reliability is improved, but user data performance is degraded due to SNR degradation
Solution Approach 1:
Instead of activating all RIS elements simultaneously, the patent activates only specific tiles corresponding to the auxiliary data bits being transmitted. This partial activation approach enables auxiliary data transmission while minimizing the impact on user data SNR, as fewer elements are perturbed from their optimal user data transmission state.
3Productivity
If auxiliary data is transmitted at the user symbol rate, then transmission speed is improved, but spatial correlation effects are amplified causing performance degradation
Solution Approach 1:
The patent prepares the RIS tile activation patterns in advance based on the auxiliary data bits to be transmitted. By pre-determining which tiles should be activated for each auxiliary data symbol, the system can transmit auxiliary data at the user symbol rate while maintaining reliable transmission, as the tile patterns are optimized beforehand to account for spatial correlation effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach maintains user data performance while enabling reliable transmission of auxiliary data by exploiting the lower data rate of auxiliary signals, particularly suitable for facilities like warehouses and factories.
Implementation Method 1
adjusting at least one of two phase states or two amplitude states of the modulation using a Reconfigurable Intelligent Surface (RIS)
Implementation Method 2
adjusting at least one of two phase states or two amplitude states of the modulation
Data Source
AI summary
Some embodiments relate to systems and methods for communication of electronic signals. An example method includes receiving a first signal having a predetermined modulation. The example method includes generating a transmission for a second signal by superimposing the second signal on the modulation of the first signal by adjusting at least one of two phase states or two amplitude states of the modulation using a Reconfigurable Intelligent Surface (RIS). The example method also includes transmitting the second signal using hierarchical modulation, the predetermined modulation and the superimposed second signal on the predetermined modulation, wherein the first signal is transmitted at a higher data rate than the second signal.