Heterogeneous Network Interference Cancellation via Subframe Segmentation
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Solution Overview
Problem
In heterogeneous radio communication networks, mobile station devices connected to picocells experience reduced transmission efficiency due to inter-cell interference from macrocells, leading to lower throughput and frequency usage efficiency.
Innovation Solution
The implementation of a communication system where base station devices with different cell radii are interconnected via backhaul links, allowing for the notification of interference cancellation information to mobile station devices, enabling them to cancel specific reference signals from interfering macrocells during specific subframes, thereby mitigating inter-cell interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heterogeneous network with picocell and macrocell is constructed to increase frequency usage efficiency, then frequency usage efficiency is improved, but inter-cell interference from macrocell to picocell increases
Solution Approach 1:
The patent segments the downlink transmission time into different subframes: first subframes for macrocell transmission and second subframes for picocell transmission. This temporal segmentation allows both cells to use the same frequency resources without simultaneous transmission, thereby maintaining frequency usage efficiency while eliminating inter-cell interference during picocell transmission periods.
Solution Approach 2:
The patent implements periodic transmission patterns where the macrocell transmits during first subframes and the picocell transmits during second subframes in a repeating cycle. This periodic action ensures that the harmful macrocell transmission is paused during picocell transmission intervals, resolving the interference issue while preserving the frequency reuse benefit.
2Strength
If mobile station device is connected to picocell to receive signal with higher strength, then signal strength is improved, but transmission throughput decreases due to inter-cell interference
Solution Approach 1:
The patent segments the transmission timeline into alternating subframes, allowing the mobile station to receive interference-free signals from the picocell during second subframes. This segmentation enables the mobile station to benefit from both strong signal strength (via picocell connection) and high throughput (via interference-free transmission periods).
Solution Approach 2:
The patent ensures continuous useful transmission by alternating between macrocell and picocell transmission in different subframes. The mobile station continuously receives signals from the picocell during second subframes without interruption from macrocell interference, maintaining both signal strength and throughput performance throughout the transmission cycle.
Data Source
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AI summary
Inter-cell Interference is efficiently mitigated or suppressed in a radio communication system constituting a heterogeneous network. In the radio communication system in which a base station device and a mobile station device communicate with each other, the base station device notifies, to the mobile station device, control information related to a cell-specific reference signal that is specific to a cell ID of another base station device different from the aforesaid base station device, the control information containing information regarding number of ports for the cell-specific reference signal.