TDD Link Direction Configuration for Interference Mitigation
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Solution Overview
Problem
The influence of transmission power from primary systems on secondary wireless communication systems, particularly in TV white spaces and mobile communication systems, has not been adequately considered, leading to decreased throughput in secondary systems due to interference.
Innovation Solution
A communication control device and method that employs a time division duplex (TDD) scheme, selecting and applying link direction configurations based on the distance between frequency channels to minimize interference, including dedicated configurations for downlink and uplink to optimize wireless communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If secondary systems use frequency bands authorized for primary systems, then frequency resource utilization is improved, but interference from primary systems to secondary systems increases
Solution Approach 1:
The patent dynamically adjusts the link direction configuration (uplink/downlink sub-frame allocation) based on the distance between frequency channels. When the frequency channel is close to a primary system channel, the system switches to a configuration with more downlink sub-frames and fewer uplink sub-frames, making the TDD configuration adaptive to interference conditions rather than static.
Solution Approach 2:
The patent changes the TDD configuration parameter (link direction configuration) based on the frequency channel distance from primary systems. By selecting different configurations (e.g., Configuration 0-6 in LTE TDD) according to the interference level, the system optimizes performance by adjusting the proportion of uplink and downlink sub-frames to minimize interference impact.
2Power
If transmission power of primary systems is increased, then coverage and signal strength are improved, but throughput of secondary systems decreases due to interference
Solution Approach 1:
The patent applies preliminary anti-action by pre-configuring the TDD link direction configuration to counteract the expected interference from primary systems. Before data transmission, the system determines the frequency channel distance and selects an appropriate TDD configuration that minimizes interference impact, thereby protecting secondary system throughput in advance rather than reacting after interference occurs.
3Productivity
If TDD configuration with more uplink sub-frames is used, then uplink throughput is improved, but interference from secondary system transmitters to primary system receivers increases
Solution Approach 1:
The patent makes the TDD configuration dynamic by adjusting the number of uplink and downlink sub-frames based on the frequency channel distance from primary systems. When operating on frequency channels close to primary system channels, the system automatically reduces the number of uplink sub-frames, thereby dynamically controlling uplink transmission activity to minimize interference to primary receivers while still allowing reasonable uplink throughput when interference is not a concern.
Data Source
AI summary
A communication control device controls wireless communication in compliance with a time division duplex (TDD) scheme. The communication control device includes a selection unit configured to select a link direction configuration for the wireless communication among a plurality of candidates for the link direction configuration which indicates a link direction in units of sub-frames of a radio frame which includes a plurality of sub-frames, and an application unit configured to apply the selected link direction configuration to the wireless communication. The plurality of candidates include at least one of a link direction configuration dedicated to a downlink and a link direction configuration dedicated to an uplink.