Sequence Determining Method for Reducing Inter-Cell Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Long Term Evolution (LTE) and New Radio (NR) systems face challenges in reducing inter-cell interference for demodulation reference signals (DMRS) due to the lack of effective sequence management, particularly when terminal devices in neighboring cells use signals based on sequences of different lengths.
Innovation Solution
A sequence determining method and apparatus that generates a second sequence based on the index of a first sequence within a sequence group, utilizing specific mathematical formulas to minimize cross-correlation between sequences of varying lengths, thereby reducing inter-cell interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If sequences of different lengths are used in neighboring cells, then sequence diversity is improved, but inter-cell interference increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the sequence length parameter based on the number of terminal devices in a cell. When the number of terminal devices exceeds a threshold, the sequence length is extended to reduce collisions and improve orthogonality, thereby reducing inter-cell interference while maintaining sequence diversity
Solution Approach 2:
The patent implements dynamics by making the sequence length configurable and adaptable rather than fixed. The system dynamically selects between different sequence lengths (e.g., 36 or 48) based on real-time network conditions and device density, allowing the system to optimize performance under varying loads
2Reliability
If a longer sequence is used, then coverage performance is improved, but interference to shorter sequences increases
Solution Approach 1:
The patent applies local quality by assigning different sequence lengths to different cells or cell groups based on their specific needs. Cells with higher device density or better coverage requirements can use longer sequences locally, while other cells use shorter sequences, thereby reducing mutual interference while maintaining overall system performance
3Ease of operation
If sequence group index is calculated using predefined rules, then sequence generation is simplified, but inter-cell interference reduction is limited
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple sequence groups with different lengths and characteristics. The system prepares these sequence groups in advance and selects appropriate sequences based on real-time conditions, allowing for proactive interference management rather than reactive adjustments
Solution Approach 2:
The patent implements universality by designing a sequence generation framework that can handle multiple sequence lengths (36, 48, and potentially other values) within a unified system. This multi-functional approach allows the same base sequence to generate multiple derived sequences with different properties, reducing the need for separate management systems
Data Source
AI summary
Embodiments of the present disclosure provide, among other implementations, sequence determining methods. One example method provides a sequence group, and one sequence group number is corresponding to at least two sequences, where one sequence is used for mapping to consecutive subcarriers, and at least one other sequence is used for mapping to equally-spaced subcarriers. In some embodiments of the present disclosure, as high as possible cross-correlation between a sending signal obtained after equally-spaced mapping is performed on a sequence in a sequence group can be determined, and a sending signal obtained after continuous mapping is performed on another sequence in the group.