Relay Node Timing Offset for OFDM Symbol Alignment
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Solution Overview
Problem
In a multi-hop relay network with integrated access and backhaul links, conventional timing solutions fail to align Orthogonal Frequency Division Multiplexing (OFDM) symbols and Demodulation Reference Signals (DMRS) for the backhaul and access links, leading to interference and performance issues when a relay node receives data from both a parent and a child node in the same slot.
Innovation Solution
The solution involves configuring a timing offset and adjustment for the uplink and downlink transmissions of the relay node's child node, using specific signaling messages to align the timing with the parent node's transmission, ensuring that data from both nodes arrives within the cyclic prefix range, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dynamic TDD with frequency division multiplexing or space division multiplexing is implemented for backhaul and access links, then spectral efficiency is improved, but OFDM symbol alignment and DMRS alignment cannot be achieved, leading to interference and performance degradation
Solution Approach 1:
The patent introduces dynamic timing adjustment mechanisms where the relay node can independently adjust timing parameters for backhaul and access links. The system dynamically configures different timing advance values and slot offsets for uplink and downlink transmissions, allowing flexible adaptation to different transmission scenarios while maintaining symbol alignment and preventing interference.
Solution Approach 2:
The patent segments the timing control into separate parameters for backhaul link and access link, allowing independent optimization of each link's timing. By configuring separate timing advance values and slot allocations for different transmission directions and partners, the system achieves precise symbol alignment without requiring uniform timing across all links.
2Adaptability or versatility
If a relay node receives data from both parent node and child node in the same slot, then network coverage is improved, but interference occurs due to timing misalignment
Solution Approach 1:
The patent implements preliminary timing adjustment where the relay node calculates and applies timing advance values before actual data transmission. The system pre-configures slot offsets and timing parameters based on detected transmission timing, ensuring that signals from parent and child nodes arrive at the relay node's receiver at appropriate times without mutual interference.
Solution Approach 2:
The patent introduces feedback mechanisms where the relay node detects actual transmission timing from parent and child nodes, then adjusts its timing parameters accordingly. The system uses detected timing information to configure receiver timing advance values, creating a closed-loop control system that continuously optimizes interference avoidance while maintaining multi-node reception capability.
Data Source
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AI summary
This application relates to the field of communications technologies, and provides a timing method and apparatus in a relay system, so that a relay device configures an uplink sending timing of a first slot or subframe for a child node of the relay device, or configures a downlink sending timing of a relay node in a first slot or subframe. This avoids interference caused due to unaligned timing and when the relay node receives data of a parent node of the relay node and data of a child node of the relay node, and avoids a transmission failure caused when the child node cannot normally use a correct timing. The method includes: sending, by a first node to a second node, an offset of a first uplink sending timing of the second node and a first amount of timing adjustment of the second node; and receiving, by the first node, data sent by the second node, where the first node is a parent node of the second node.