IRS Phase-Shift Allocation for Cognitive Radio Spectrum Perception
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Solution Overview
Problem
Existing cognitive radio networks using intelligent reflecting surfaces (IRS) do not effectively utilize IRS in the perception stage, leading to inefficient resource allocation and low perception performance, resulting in interference to primary users and reduced transmission rates for secondary users.
Innovation Solution
An optimization method for resource allocation in a perception-enhanced cognitive radio network that involves acquiring channel state information, defining IRS phase-shift matrices, and establishing an optimization model to optimize beamforming vectors and phase-shift matrices in both the perception and transmission stages to improve spectrum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If IRS is not used in the perception stage, then hardware resources are wasted, but the system complexity is reduced
Solution Approach 1:
The IRS is designed to perform dual functions: spectrum perception and data transmission. By configuring the IRS to reflect signals during both perception and transmission stages, the system achieves multi-functionality with a single hardware component, improving perception performance without proportionally increasing system complexity
Solution Approach 2:
The IRS is pre-configured with phase shift parameters before the perception stage begins. This preliminary configuration enables the IRS to assist in spectrum perception from the outset, improving detection accuracy without requiring complex real-time adjustments during the perception process
2Reliability
If SBS reduces transmit power to constrain interference to primary users, then primary user QOS is protected, but secondary user transmission rate decreases
Solution Approach 1:
The IRS acts as an intermediary between the SBS and both primary and secondary users. By reflecting and steering signals through the IRS, the system can maintain higher transmit power while the IRS controls the signal directions, thus protecting primary users from interference while enabling secondary users to achieve higher transmission rates
Solution Approach 2:
The IRS applies different phase shift configurations to different spatial regions: one configuration directs signals toward secondary users to enhance their reception, while another configuration steers signals away from primary users to minimize interference. This spatial differentiation allows simultaneous optimization of both user groups
3Object-affected harmful factors
If opportunistic access is used, then primary user interference is avoided, but secondary user average transmission rate is low
Solution Approach 1:
The system dynamically switches between opportunistic access and spectrum sharing modes based on IRS-assisted spectrum perception results. When the spectrum is detected as idle, the system allows secondary users to transmit; when occupied, it switches to opportunistic mode. This dynamic adaptation maximizes secondary user transmission opportunities while protecting primary users
4Productivity
If spectrum sharing is used, then secondary user transmission rate increases, but interference to primary users cannot be constrained
Solution Approach 1:
The system implements feedback-based spectrum sharing where IRS continuously monitors spectrum usage and provides real-time information to the SBS. Based on this feedback, the SBS adjusts its transmit power and the IRS adjusts its phase shift configuration to maintain secondary user transmission rates while dynamically controlling interference levels to primary users
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
The method enhances spectrum efficiency by reducing false alarm probabilities and increasing transmission rates for secondary users while maintaining high quality of service for primary users, utilizing IRS to assist in spectrum perception and transmission.
Implementation Method 1
uses an intelligent reflecting surface (IRS) to assist in data transmission
Data Source
AI summary
Disclosed is an optimization method for resource allocation in a perception-enhanced cognitive radio network based on an IRS (intelligent reflecting surface). The method includes: acquiring BS (base station)-to-IRS and IRS-to-user channel state information; defining diagonal phase-shift matrices of the IRS in perception stage and transmission stage, and establishing an optimization model according to the channel state information; using the optimization model to optimize that the diagonal phase-shift matrix of the IRS in the perception stage assists the secondary base station (SBS) in perceiving a spectrum occupancy of a primary network; entering the transmission stage, and using the optimization model to optimize beamforming vectors of the SBS and the diagonal phase-shift matrices of the IRS in the transmission stage in the case of different perception results; transmitting transmission information according to optimization results to achieve an improvement in a spectrum efficiency of a system when constraints interfere with primary users.