Relay Node Cooperative Transmission for Wireless Latency Reduction
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Solution Overview
Problem
Wireless communication systems using relay nodes experience increased latency in downlink signal transmission, which affects the quality of service for time-sensitive applications like VoIP and video streaming due to the need for re-transmissions, leading to decreased performance and frame synchronization impairments.
Innovation Solution
Implementing a method where relay nodes cooperatively transmit downlink signals with base stations, using channel quality measurements to determine the integrity and timing of signal re-transmissions, and combining signals to reduce latency by avoiding unnecessary waiting for acknowledgement signals, thereby improving receiver performance and reducing packet delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If relay nodes re-transmit downlink signals to extend coverage and improve system capacity, then signal reception quality is improved, but transmission latency increases
Solution Approach 1:
The base station transmits the downlink signal in advance to the relay node before the relay node needs to forward it to the wireless device. This preliminary transmission allows the relay node to have the signal ready for immediate re-transmission, reducing the overall latency while maintaining the coverage extension benefit
Solution Approach 2:
The base station acts as an intermediary by pre-providing the downlink signal to the relay node. This mediator approach allows the relay node to forward the signal without needing to request or wait for acknowledgment, thus reducing latency while maintaining signal reception quality
2Reliability
If relay nodes wait for acknowledgement signals before re-transmitting, then signal integrity is maintained, but transmission delay increases
Solution Approach 1:
The base station provides the downlink signal to the relay node in advance, before the relay node needs to forward it. This preliminary provision of the signal eliminates the need for the relay node to wait for acknowledgments or requests, reducing transmission delay while maintaining signal integrity through the pre-established signal path
Solution Approach 2:
The acknowledgment and request signal exchange is extracted and eliminated from the relay node's transmission process. By removing this feedback loop, the relay node can re-transmit signals immediately based on pre-received downlink signals, reducing delay while maintaining integrity through the base station's coordinated transmission
3Productivity
If relay nodes cooperatively transmit with base stations, then system capacity is improved, but transmission coordination complexity increases
Solution Approach 1:
The base station and relay node transmit the downlink signal simultaneously to the wireless device, merging their transmission resources. This combining approach improves system capacity by utilizing multiple transmitters for the same signal, while the complexity is managed by the base station's centralized control over the relay node's transmission timing and parameters
Data Source
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AI summary
Methods, devices and systems for improved transmission in a remote node-based wireless communication system are provided. In one embodiment, a method of wireless communication comprises receiving a downlink signal from a first node, demodulating said received downlink signal, generating a channel quality measurement ("CQM") value of said demodulated downlink signal, determining said CQM value exceeds a first threshold, modulating said demodulated downlink signal to form a processed downlink signal, and cooperatively transmitting said processed downlink signal with said first node to a wireless device.