Supplemental RIS Layout for Higher-Throughput Downlink Coverage

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Solution Overview

Problem

Existing wireless communication systems face challenges in achieving high spectral efficiency and efficient power consumption in downlink communications due to suboptimal placement of reconfigurable intelligent surfaces (RIS) and the high power consumption of active antenna units (AAUs).

Innovation Solution

Implementing a secondary RIS in addition to a primary RIS, where the primary RIS facilitates both uplink and downlink communications, while the secondary RIS is dedicated to downlink communications, allowing for dynamic configuration and power-efficient signal reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single RIS is used for both uplink and downlink communications, then device complexity is reduced, but downlink throughput and coverage are limited

Engineering Contradiction:

Improvedownlink throughputVSAvoidRIS configuration complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the RIS functionality into two separate surfaces: a first RIS for bidirectional communications and a second RIS for downlink communications only. This segmentation allows each RIS to be optimized for its specific function, thereby improving downlink throughput and coverage without significantly increasing overall system complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first RIS is designed with multi-functionality to handle both uplink and downlink communications, while the second RIS is dedicated solely to downlink communications. This universal approach allows the system to achieve enhanced downlink performance by utilizing the specialized second RIS for downlink-only operations

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If RIS locations are optimized for spectral efficiency, then communication quality improves, but system flexibility and adaptability are reduced

Engineering Contradiction:

Improvespectral efficiencyVSAvoidRIS placement flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

By segmenting the RIS system into two separate surfaces with different functional assignments, the patent enables flexible placement of each RIS based on specific performance requirements. The first RIS can be positioned to optimize uplink performance while the second RIS is positioned to optimize downlink spectral efficiency, allowing the system to adapt to various deployment scenarios

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic configuration capabilities where the base station can flexibly configure the RISs based on real-time communication needs. This allows the system to adapt RIS placements and configurations dynamically to optimize spectral efficiency while maintaining placement flexibility according to specific downlink communication requirements

Inventive Principle:

Principle #15Dynamics

3Area of stationary object

If active antenna units are used to increase cell coverage, then coverage area expands, but power consumption increases

Engineering Contradiction:

Improvecell coverage areaVSAvoidpower consumption

Core Design Contradiction:

Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent replaces active antenna units with passive RIS surfaces that utilize electromagnetic wave reflection and refraction principles. The RISs can be configured to steer and focus radio waves to extend cell coverage without requiring the high power consumption associated with active amplification and signal processing in traditional active antenna systems

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of the RIS system by configuring the second RIS specifically for downlink communications with optimized reflection coefficients and phase shifts. This allows the system to achieve extended coverage area through intelligent wave manipulation rather than high-power transmission, thereby reducing overall power consumption while maintaining coverage expansion

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12627334B2Supplemental reconfigurable intelligent surfaces for downlink communication

Publication Date: 2026.05.12 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communication are described. A communication device, such as a user equipment (UE) may receive a configuration (for example, via control signaling) of a set of reconfigurable intelligent surfaces (RISs). The UE may select a primary RIS for bidirectional wireless communication (for example, uplink and downlink) and one or more secondary RISs for unidirectional wireless communication (for example, downlink) based on the configuration. The UE may use the one or more secondary RISs to enable higher throughput and extended coverage in the wireless communication system, for example, for downlink. The UE may communicate with the base station using the primary RIS, or the secondary RIS, or both.