Dynamic CRS Power Management for Interference Reduction
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Solution Overview
Problem
Cells without active UE connections in cellular networks consume power due to continuous broadcasting of Cell Reference Symbols (CRS), causing interference and reducing throughput, especially at cell edges, and reducing CRS power compromises cell size and channel estimation quality.
Innovation Solution
A network node method to dynamically adjust CRS power by reducing it in cells not actively serving UEs, switching to a lower power mode when no UEs are connected, and increasing power in cells with high UE load to balance interference and detection capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If CRS power is reduced in cells without active UEs, then power consumption and interference are reduced, but cell size and channel estimation quality are compromised
Solution Approach 1:
The patent applies dynamics by making CRS power transmission adaptive rather than fixed. The network node dynamically adjusts CRS power levels based on real-time detection of active UEs in each cell. When no UEs are detected, the node reduces CRS power to save energy and reduce interference. When UEs are present, the node restores normal power levels to maintain channel estimation quality. This dynamic adjustment resolves the contradiction between continuous power consumption and on-demand reliability.
Solution Approach 2:
The patent changes the power parameter of CRS transmission based on cell occupancy status. By monitoring UE presence and adjusting the transmission power parameter accordingly, the system optimizes the balance between energy efficiency and measurement reliability. The power parameter is modified from a static value to a variable that responds to network conditions, allowing the system to accept reduced power when reliability requirements are lowered (no active UEs) and restore full power when reliability is needed (active UEs present).
2Object-generated harmful factors
If CRS power is reduced in empty cells, then interference to neighboring cells is reduced, but UE detection capability is compromised
Solution Approach 1:
The system dynamically adjusts CRS power based on detected UE presence. When cells are identified as empty (no active UEs), the CRS power is reduced to minimize interference to neighboring cells. When UEs are detected in a cell, the CRS power is restored to ensure adequate signal strength for UE detection and measurement. This dynamic control allows the system to accept reduced interference when detection capability is not needed, and restore full detection capability when UEs are present.
3Reliability
If CRS are transmitted continuously in all cells, then UE connectivity is maintained, but power consumption increases
Solution Approach 1:
The patent implements dynamic CRS transmission by continuously monitoring UE presence in each cell and adjusting transmission accordingly. Cells without active UEs have CRS transmission reduced or suspended, while cells with active UEs maintain normal transmission. This dynamic approach maintains connectivity reliability where needed while significantly reducing overall power consumption across the network.
Solution Approach 2:
The patent extracts the CRS transmission function from being universally applied to all cells and makes it selective. By identifying and excluding empty cells from full-power CRS transmission, the system removes unnecessary energy consumption while preserving the essential connectivity function in cells that actually have UEs. This extraction of the transmission function from unnecessary contexts resolves the contradiction between continuous connectivity and power consumption.
Data Source
AI summary
A method performed by a network node for managing power of Cell Reference Symbols, CRS, wherein the network node operates one or more cells and the network node is configured to transmit the CRS in a first power mode. When the network node identifies a first cell which is not actively serving any UEs, which cell is also referred to as an empty cell, the network node reduces the power of the CRS in the first cell in relation to the first power mode. By reducing the power of the CRS, the overall interference of the CRS from the empty cell is reduced, thereby enhancing the performance in cells actively serving UEs.