Cooperative Interference Mitigation in Wireless Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communications systems face challenges in effectively mitigating inter-cell interference (ICI) due to the unilateral nature of existing interference mitigation techniques, which do not fully leverage knowledge and actions from multiple cell-sites, leading to suboptimal performance, especially in VoIP applications with high connection demands.
Innovation Solution
A system and method that coordinates between multiple controllers to establish cooperative agreements, allowing for joint interference mitigation at both the source and receiver ends by scheduling transmission opportunities based on link gain imbalances and configuration information, using techniques such as cooperative ICI mitigation and power control to minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If unilateral interference mitigation techniques are used at only one end (transmitter or receiver), then the implementation complexity is reduced, but the interference mitigation performance is suboptimal
Solution Approach 1:
The patent combines interference mitigation actions at both the transmitter end (controller) and receiver end (communications device) into a coordinated system. The controller establishes cooperative agreements with other controllers and schedules transmission opportunities, while the communications device measures channels to multiple controllers and provides feedback indicators. This merging of unilateral techniques into a bilateral coordinated system resolves the contradiction by achieving better interference mitigation performance through joint action while managing complexity through structured coordination protocols.
2Reliability
If multi-cell coordination is implemented to reduce ICI, then the interference mitigation performance is improved, but the coordination signaling cost and complexity increase
Solution Approach 1:
The patent segments the multi-cell coordination problem into manageable components: (1) controller-to-controller coordination for establishing cooperative agreements on transmission scheduling, (2) downlink configuration information transmission from controller to device, (3) device measurement of channels to multiple controllers, and (4) uplink feedback of operating condition indicators. This segmentation reduces coordination signaling complexity by organizing multi-cell coordination into structured, modular information exchange steps while maintaining improved interference mitigation performance.
Solution Approach 2:
The communications device acts as an intermediary that measures channels to multiple controllers and provides feedback indicators about operating conditions to its serving controller. This intermediary role enables the controller to make informed scheduling decisions without requiring direct complex signaling between all pairs of controllers, thereby reducing overall coordination signaling complexity while maintaining effective interference mitigation.
3Object-generated harmful factors
If transmit power is minimized to reduce interference to co-channel cells, then the interference level is reduced, but the signal quality at the receiver may deteriorate
Solution Approach 1:
The patent implements dynamic transmit power control where the controller schedules transmission opportunities based on real-time operating conditions reported by the communications device. The device measures channels to multiple controllers and provides feedback indicators that enable the controller to adjust transmit power dynamically - using higher power when channel conditions are poor and lower power when conditions are good. This dynamic adjustment resolves the contradiction by adapting power levels to actual channel conditions rather than using fixed minimized power, thereby maintaining signal quality while still reducing interference when possible.
Solution Approach 2:
The communications device provides feedback indicators to the controller about its operating conditions based on channel measurements to multiple controllers. This feedback enables the controller to make informed decisions about transmit power and transmission scheduling, resolving the contradiction by using real-time channel state information to balance interference reduction with signal quality maintenance. The feedback loop allows the system to adapt power levels based on actual receiver conditions rather than using fixed power minimization.
4Productivity
If frequency reuse is increased to improve spectral efficiency, then the data rate is improved, but the inter-cell interference increases
Solution Approach 1:
The controller establishes cooperative agreements with other controllers in advance, pre-coordinating transmission schedules and frequency usage patterns. This preliminary action allows the system to implement frequency reuse patterns that are optimized to minimize interference from the outset, rather than reacting to interference after it occurs. By pre-coordinating which cells transmit on which frequencies and when, the system can achieve high spectral efficiency through aggressive frequency reuse while maintaining low interference levels through advance planning and coordination.
Data Source
AI summary
A system and method for interference mitigation in a wireless communications system are provided. A method for interference mitigation in a controller includes coordinating with other controllers to establish a cooperative agreement, receiving information from a communications device served by the controller, scheduling a transmission opportunity for the communications device based on an indicator and the cooperative agreement, and receiving a transmission from the communications device at the scheduled transmission opportunity.