Central Controller Interference Management in Wireless Systems
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Solution Overview
Problem
Existing wireless telecommunications systems face challenges in managing uplink inter-cell interference, particularly in high spectrum efficiency systems like Evolved Universal Terrestrial Radio Access (UTRA), where existing Radio Resource Management techniques fail to address long-term interference and do not coordinate effectively between radio access nodes to prevent unnecessary handovers and optimize system capacity.
Innovation Solution
The proposed solution involves a method where a central controller interacts with access points to monitor and control uplink interference, taking short-term and long-term actions to maintain acceptable interference levels across multiple cells, including autonomous channel management and coordinated load balancing to minimize interference and maximize system capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If dynamic channel allocation is used to reduce interference on a short time scale, then interference levels are kept at close-to-optimum values, but long-term interference events and repeated occurrence of high interference on certain sub-carrier frequencies are not addressed
Solution Approach 1:
The patent implements a two-tier interference management system that dynamically adapts to different time scales. The first RRM technique operates on a short time scale for immediate interference response, while the second RRM technique operates on a longer time scale to address persistent interference patterns. This dynamic multi-timescale approach allows the system to respond appropriately to both transient and chronic interference conditions.
Solution Approach 2:
The patent employs anticipatory actions by monitoring and identifying persistent interferers over the longer time scale before they cause significant degradation. The second RRM technique performs preliminary interference management by detecting patterns of repeated high interference on certain sub-carriers and taking preventive measures, rather than merely reacting to interference after it occurs.
2Productivity
If load balancing is used to distribute traffic among cells, then system capacity is optimized, but unnecessary handovers may occur increasing transport network load
Solution Approach 1:
The patent implements a feedback mechanism where the longer time scale RRM technique continuously monitors interference patterns and handover performance. By analyzing this feedback information about persistent interferers and actual handover necessity, the system can make informed decisions about load balancing, triggering handovers only when truly necessary rather than based solely on load metrics, thereby reducing unnecessary handovers and associated network load.
3Object-affected harmful factors
If fractional load is used to reduce inter-cell interference by using only a subset of available sub-carriers, then interference is reduced, but the technique becomes non-applicable in evolved UTRA networks which require high spectrum efficiency
Solution Approach 1:
The patent applies local quality by implementing interference management selectively on specific sub-carriers affected by persistent interferers rather than uniformly reducing usage across all sub-carriers. The second RRM technique identifies and targets only the specific frequency resources experiencing chronic interference problems, allowing full utilization of clean spectrum resources while mitigating interference locally where needed, thus maintaining high overall spectrum efficiency.
Data Source
AI summary
A method for controlling uplink transmissions from a user device to an access point in a wireless telecommunications system is described. Each access point defines a communications cell, and the method comprises monitoring interference in an uplink channel at an access point, performing interference control actions at the access point when monitored interference exceeds a first predetermined level, monitoring occurrences of such control actions at the access point, and if a number of such occurrences exceeds a predetermined level, performing interference control actions with reference to a plurality of cells at a central controller of the telecommunications system, which central controller is operable to control a plurality of access points.