LIS Precoding for OAM Wireless Links Without OAM Antennas
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Solution Overview
Problem
Existing wireless communication systems struggle to support orbital angular momentum (OAM) communication when network nodes lack OAM antennas, leading to reduced data transmission rates for terminals capable of OAM communication.
Innovation Solution
An electronic apparatus and method that estimates a channel between a network node and an intelligent reflecting surface (LIS), pre-codes a plane wave signal based on this channel to create an equivalent OAM channel model, and transmits the pre-coded signal, enabling OAM communication even without OAM antennas at the network node.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OAM communication is implemented between network terminals and network nodes, then spectral efficiency and communication performance are improved, but device complexity increases due to requiring OAM antennas at network nodes
Solution Approach 1:
The patent introduces an intelligent reflecting surface (LIS) as an intermediary component between the network node and OAM terminal. The LIS converts plane waves from conventional antennas into vortex waves carrying OAM, enabling OAM communication without requiring OAM antennas at the network node. This mediator approach allows spectral efficiency improvement while avoiding the complexity of OAM antenna implementation at network nodes.
Solution Approach 2:
The patent creates a virtual OAM channel by pre-coding plane wave signals to simulate the effect of direct OAM transmission. Through channel estimation and pre-coding matrix design, the system copies the functional characteristics of OAM communication using conventional plane wave antennas combined with LIS, avoiding the need for physical OAM antennas at network nodes.
2Adaptability or versatility
If OAM communication is established in non-line-of-sight scenarios, then communication coverage is improved, but signal quality deteriorates due to difficulty in creating equivalent OAM channel models
Solution Approach 1:
The patent performs channel estimation between the network node and LIS in advance, and pre-codes the plane wave signals before transmission based on the estimated channel characteristics. This preliminary action allows the system to compensate for non-line-of-sight propagation effects and create an equivalent OAM channel model, ensuring reliable signal quality while extending communication coverage to scenarios without direct line of sight.
3Device complexity
If plane wave signals are transmitted without pre-coding, then device complexity is reduced, but the ability to create equivalent OAM channel models deteriorates
Solution Approach 1:
The patent changes the parameters of the transmitted signal by applying pre-coding based on channel estimation results. The pre-coding matrix modifies the plane wave signal parameters (phase, amplitude distribution) to create the equivalent OAM channel model. This parameter transformation enables accurate OAM simulation while keeping the physical antenna structure simple and conventional.
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
Enables OAM communication between network terminals and nodes lacking OAM antennas by converting plane waves into vortex waves using an LIS, improving data transmission rates and spectral efficiency.
Implementation Method 1
Electromagnetic waves have both linear momentum and angular momentum. The angular momentum may be decomposed into a spin angular momentum (SAM) and an orbital angular momentum (OAM). The OAM is a result of a change of a phase of a wave relative to an azimuth θ around a propagation axis of the wave.
Implementation Method 2
The OAM is a result of a change of a phase of a wave relative to an azimuth θ around a propagation axis of the wave. The change results in a spiral phase distribution (Φ=l*θ), where l represents the number of OAM modes
Implementation Method 3
The LIS is a completely new revolutionary technology. A large number of low-cost passive reflective components are integrated on a plane to intelligently reconfigure a wireless propagation environment
Data Source
AI summary
The present disclosure provides an electronic device and method for wireless communication, and a computer readable storage medium. The electronic device comprises: a processing circuit, configured to estimate a first channel between a network node and an intelligent reflecting surface; pre-code, at least based on the estimated first channel, a plane wave signal sent by the network node, so that a channel model between the network node and a network terminal is equivalent to an orbital angular momentum channel model between the intelligent reflecting surface and the network terminal; and send the pre-coded plane wave signal.