Reference Signal Transmission for Inter-Cell Interference Cancellation
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Solution Overview
Problem
In LTE wireless communication systems, interference between adjacent cells due to shared frequency bands leads to high bit error rates in uplink data transmission, particularly in TDD-mode cells with differing uplink-downlink subframe configurations, causing inter-cell interference that worsens with dynamic TDD technologies.
Innovation Solution
A reference signal transmission method where a first network device sends a reference signal to a second network device based on configuration information, allowing the second device to cancel interference by estimating the channel and demodulating uplink data, thereby improving data reception accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a same working frequency range is configured for adjacent LTE cells, then spectrum resource utilization is improved, but inter-cell interference increases causing high bit error rate in uplink data transmission
Solution Approach 1:
A reference signal is introduced as an intermediary carrier between the interfering base station and the affected user equipment. The reference signal conveys interference channel information from the first base station to the second base station, enabling the affected system to compensate for interference without direct interaction between interfering parties.
Solution Approach 2:
The system establishes a feedback loop where the first base station transmits reference signals that carry channel state information about the interference path. The second base station receives and processes this information to adjust its uplink reception parameters, creating a closed-loop interference management system.
2Adaptability or versatility
If dynamic TDD technology is used to flexibly adjust uplink-downlink subframe configurations, then network adaptability is improved, but inter-cell interference worsens due to configuration differences between adjacent cells
Solution Approach 1:
The reference signal transmission configuration is made dynamic to match the flexible TDD subframe configurations. The system can adaptively adjust reference signal parameters according to changing uplink-downlink configurations, maintaining interference compensation effectiveness despite dynamic network reconfiguration.
Solution Approach 2:
The reference signal is transmitted in advance during downlink subframes to provide interference channel information before uplink transmission occurs. This preliminary action allows the affected base station to prepare interference compensation parameters ahead of time, ensuring continuous protection against interference even during dynamic reconfiguration.
3Productivity
If downlink subframes are increased to meet downlink data transmission demands, then downlink throughput is improved, but uplink interference from adjacent cells increases
Solution Approach 1:
The interference channel information is extracted from the overall downlink signal through dedicated reference signal transmission. By separating the interference characterization function from normal data transmission, the system can accurately identify and compensate for interference components without affecting downlink throughput performance.
Data Source
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AI summary
Embodiments of the present invention provide a reference signal transmission method and apparatus, a network device, and user equipment. The method in the embodiments of the present invention includes: sending, by a first network device NE1 to which a first cell CELL1 belongs, a first reference signal RS based on first configuration information to a second network device NE2 to which a second cell CELL2 belongs, where the first configuration information includes information used to indicate a time-frequency resource used by the NE1 for sending the first RS. The reference signal transmission method provided in the embodiments of the present invention is used to resolve a prior-art problem of a high bit error rate of uplink data due to interference.