Heterogeneous Network Control Channel Interference Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heterogeneous networks face interference management challenges due to the significantly lower transmit power of low power nodes compared to macro eNBs, particularly in the control channels (PCFICH, PDCCH, PHICH) which affects the robust reception and service area of low power cells.
Innovation Solution
Implementing a carrier aggregation based solution with reduced transmit power on the control region of macro cells, while maintaining PDSCH transmit power, and using extended PDCCH (E-PDCCH) regions within the PDSCH regions to manage interference and support both legacy and advanced UEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low power nodes transmit control channels at higher power to improve reception robustness, then control channel reliability improves, but interference to other low power nodes and macro cells increases
Solution Approach 1:
The patent applies local quality by differentiating transmit power levels for control channels based on the serving cell type. Macro eNBs transmit control channels at higher power to ensure coverage, while low power nodes transmit at lower power to minimize interference. This localized power adjustment allows each node to optimize its control channel transmission according to its specific role and coverage requirements, resolving the contradiction between reception robustness and interference generation.
2Area of stationary object
If low power nodes increase transmit power to expand service area, then coverage area increases, but interference to macro cell control channels increases
Solution Approach 1:
The patent applies parameter changes by adjusting the transmit power parameter for control channels based on the serving cell's power class. Low power nodes operate with reduced control channel transmit power compared to macro eNBs, which allows them to extend their service area without generating excessive interference to macro cell control channels. This parameter differentiation enables low power nodes to achieve broader coverage while maintaining acceptable interference levels.
3Adaptability or versatility
If macro eNBs maintain high control channel power for legacy UE support, then legacy UE compatibility is maintained, but interference to low power nodes increases
Solution Approach 1:
The patent applies local quality by implementing different control channel transmit power strategies for macro eNBs and low power nodes. Macro eNBs maintain higher control channel power specifically to support legacy UEs that require robust control channel reception, while low power nodes operate at lower power to minimize interference. This localized differentiation in power transmission allows the system to maintain legacy compatibility at macro cells while protecting low power node operations from excessive interference.
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
A method for managing control channel interference is provided. The method includes a first access node performing at least one of blanking and transmitting at lower than nominal transmit power on at least a portion of a control channel. The method further includes the first access node applying at least one of blanking and transmitting at lower than nominal transmit power only on the control region of chosen subframes, wherein a second access node transmits the control region of the chosen subframes at nominal transmit power.