Relay Node Reference Signal Demodulation via High-Layer Signaling
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Solution Overview
Problem
Relay nodes in wireless communication systems face challenges in demodulating control channels received from base stations due to uncertainty about the reference signal allocated to the radio resource region, especially when control and data channels have different transmission ranks.
Innovation Solution
The method involves using high-layer signaling to inform the relay node about the reference signal applied to the control channel, allowing accurate demodulation, and employing DM-RS for both R-PDCCH and R-PDSCH to enable efficient spatial multiplexing and reduce signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a relay node uses cell-specific reference signals for demodulation, then channel measurement can be performed, but the relay node cannot accurately determine which reference signal is allocated to the control channel when control and data channels have different transmission ranks
Solution Approach 1:
The patent introduces DM-RS (Demodulation Reference Signal) as an intermediary specifically for control channel demodulation. The DM-RS is transmitted together with the control channel and provides a dedicated reference for demodulation, eliminating the ambiguity of using cell-specific reference signals. This intermediary signal resolves the contradiction by providing clear identification without increasing overall system complexity.
Solution Approach 2:
The patent segments the reference signal functionality into different types: DM-RS for control channel demodulation and cell-specific reference signals for channel measurement. This segmentation allows each reference signal type to serve its specific purpose efficiently, with DM-RS providing accurate control channel demodulation while cell-specific signals handle measurement tasks.
2Reliability
If different reference signals are used for control and data channels, then accurate demodulation is possible, but signaling overhead increases
Solution Approach 1:
The patent makes DM-RS universal by using it for both control channel (R-PDCCH) and data channel (R-PDSCH) demodulation. The same reference signal structure and transmission mechanism are applied to both channels, eliminating the need for separate reference signal configurations and reducing signaling overhead while maintaining demodulation accuracy.
Solution Approach 2:
The patent merges the reference signal mechanisms for control and data channels by using DM-RS for both. Instead of maintaining separate reference signal systems, the DM-RS is combined as a unified solution that serves both channels, reducing the total signaling overhead while preserving the ability to accurately demodulate both control and data channels even when they have different transmission ranks.
Data Source
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AI summary
The present invention relates to a method of a Relay Node (RN) using a reference signal. The method includes receiving information about a Dedicated Reference Signal (DRS) which is used to demodulate a control channel via high-layer signaling from an evolved-NodeB (eNB), receiving control information through the control channel from the eNB, receiving data through a data channel from the eNB, and demodulating the control information and the data. The control information is demodulated using a DRS indicated by the information about the DRS, and the data are demodulated using a DRS indicated by the control information.