Reference Signal Mapping for 5G Subcarrier Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the 5G wireless communication system, different subcarrier spacing values applied to neighboring cells can cause interference between reference signals, leading to deteriorated channel estimation accuracy.
Innovation Solution
A wireless transmission device and method that generates a reference signal using a sequence length corresponding to a first ratio of the subcarrier spacing set for transmission data to the maximum settable subcarrier spacing, and maps this sequence to subcarriers at intervals reciprocal to the first ratio, allowing for improved channel estimation accuracy by reducing inter-cell interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different subcarrier spacing values are applied to neighboring cells to improve system adaptability and performance, then the system can better serve diverse communication needs, but interference between reference signals increases and channel estimation accuracy deteriorates
Solution Approach 1:
The reference signal is segmented into multiple parts, each mapped to different subcarriers with specific mapping intervals. This segmentation allows the reference signal to be distributed across the frequency domain in a way that reduces overlap and interference with neighboring cells' reference signals, thereby maintaining channel estimation accuracy while supporting multiple subcarrier spacing values.
Solution Approach 2:
Different mapping intervals are applied to different parts of the reference signal sequence, with the mapping interval determined by the subcarrier spacing. This local differentiation ensures that each segment of the reference signal is optimally positioned to minimize interference in its specific frequency region, enabling the system to handle diverse subcarrier spacing configurations without sacrificing measurement precision.
2Reliability
If subcarrier spacing is increased to reduce phase noise interference and achieve low delay in high frequency bands, then data transmission performance improves, but reference signal interference from neighboring cells with different subcarrier spacing increases
Solution Approach 1:
The reference signal mapping transitions from a simple one-to-one subcarrier mapping to a multi-dimensional mapping pattern that considers both the reference signal sequence index and the subcarrier spacing. By introducing the mapping interval as an additional dimension, the system can accommodate different subcarrier spacing values while maintaining reference signal orthogonality and reducing inter-cell interference.
Solution Approach 2:
The mapping interval parameter is dynamically adjusted based on the subcarrier spacing value. When subcarrier spacing changes, the mapping interval is recalculated to maintain the optimal relationship between the reference signal sequence length and the available subcarriers. This parameter adaptation allows the system to maintain reference signal integrity across different frequency bands and subcarrier spacing configurations.
Data Source
AI summary
When a plurality of the subcarrier spacing values are applied, a reference signal is generated by using a sequence having a sequence length corresponding to a first ratio of a first subcarrier spacing set for transmission data to the maximum settable subcarrier spacing. The sequence of the reference signal is mapped to a frequency resource at mapping intervals in accordance with a second ratio which is the reciprocal of the first ratio, and the transmission data and the reference signal are transmitted.