IRS Retro-Reflection Beam Training for Low-Latency Link Pairing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing beam training methods for intelligent reflecting surfaces (IRS) in mmWave and terahertz cellular systems are inefficient and introduce significant latency, especially for mobile users, due to the need for exhaustive search and re-establishment of beam pairs, which worsens with user mobility.
Innovation Solution
A method and system that configures IRS in retro-reflection mode to determine optimal beam pairs for BS-IRS, IRS-UE, and UE-IRS links by utilizing retro-reflection and determining beam pairs while the UE or BS is in an idle state, enabling faster beam training through coordinated beam pairing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If exhaustive beam training search is performed to determine optimal beam pairs for IRS-assisted links, then beamforming accuracy is improved, but beam training latency increases significantly
Solution Approach 1:
The patent applies preliminary action by performing retro-reflection beam training to pre-determine optimal beam pairs for both BS-IRS and UE-IRS links before actual data transmission. The base station configures the IRS with predetermined beam pairs that will be used for subsequent communication, eliminating the need for exhaustive real-time beam search during data transmission. This preparatory beam pairing process reduces the beam training latency while maintaining accurate beamforming through pre-optimized beam configurations.
2Reliability
If beam pairs are re-established frequently to track mobile users, then connection reliability is improved, but system overhead and latency increase
Solution Approach 1:
The patent performs preliminary retro-reflection beam training to establish optimal beam pairs in advance, creating a foundation for tracking mobile users without frequent re-establishment. The predetermined beam pairs at the IRS enable the system to maintain reliable connections for mobile users by having pre-configured alternative beam paths ready, reducing the need for frequent exhaustive beam searches when user position changes occur.
3Speed
If retro-reflection mode is configured for IRS to reduce beam training latency, then beam training speed is improved, but beamforming flexibility is reduced
Solution Approach 1:
The patent applies preliminary action by configuring the IRS with predetermined beam pairs through retro-reflection before actual communication. This preliminary configuration establishes a set of optimal beam pairs that balance speed and flexibility - the retro-reflection process quickly identifies suitable beam pairs, and these pre-determined pairs are then used for subsequent transmissions, maintaining both fast beam training and adequate beamforming adaptability for different communication scenarios.
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
Reduces beam training latency and enhances beamforming efficiency by optimizing beam pairs using retro-reflection techniques, improving connectivity and reducing latency in IRS-assisted cellular systems.
Implementation Method 1
configuring the IRS in a retro-reflection mode to reflect a received beam in same direction of reception of the beam
Data Source
AI summary
Disclosed is a method and device for beam training for an IRS assisted cellular system. The method performed by BS in the IRS assisted cellular system includes configuring the IRS in a retro-reflection mode to reflect a received beam in same direction of reception of the beam and determining a BS optimal Tx-Rx beam pair for a BS-IRS link. The method includes: configuring the IRS to receive a beam from the UE; configuring the IRS to determine an IRS optimal Tx-Rx beam pair for an IRS-UE link and receiving signalling information from the UE indicating the IRS optimal Tx-Rx beam pair; and transmitting to the UE, a beam through the BS optimal Tx-Rx beam pair which is received at the UE through the UE optimal Tx-Rx beam pair, wherein the IRS reflects the beam transmitted by the BS to the UE through the IRS optimal Tx-Rx beam pair.