NOMA Sequence Selection for Low Cross-Correlation Uplink Scrambling
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Solution Overview
Problem
Existing Non-Orthogonal Multiple Access (NOMA) signature sequence designs do not guarantee evenly distributed cross correlation, leading to higher interference between data streams in lightly loaded systems, particularly affecting UEs that select sequences with much worse cross correlation.
Innovation Solution
Techniques for selecting sequences with improved cross correlation by optimizing the pre-configured sequence set, ensuring lower cross correlation between sequences used in the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing NOMA signature sequence designs are used, then the system supports multiple users, but cross correlation between sequences is not evenly distributed leading to higher interference
Solution Approach 1:
The patent modifies the parameters of the pre-configured sequence set by optimizing the selection and configuration of sequences to achieve more uniform cross-correlation distribution. This involves changing the mathematical parameters and structural properties of the sequences to minimize interference while maintaining system capacity.
Solution Approach 2:
The patent applies preliminary optimization to the sequence set configuration before actual NOMA operations. By pre-configuring sequences with improved cross-correlation properties and providing indicators to UEs, the system proactively eliminates interference issues before they occur during data transmission.
2Ease of manufacture
If sequence sets are optimized for fixed size, then design simplicity is maintained, but adaptability to varying system load is reduced
Solution Approach 1:
The patent introduces dynamic adaptability to the sequence selection process by providing UEs with indicators about the number of sequences to select based on current system load conditions. This allows the system to transition from static fixed-size sequence sets to dynamic adaptive sequence selection, where UEs can adjust their sequence choices according to real-time network conditions.
Solution Approach 2:
The patent segments the sequence selection process into multiple stages: pre-configuring a comprehensive sequence set, then allowing UEs to select appropriate subsets based on system load indicators. This segmentation enables both the simplicity of pre-configured designs and the flexibility of adaptive selection by dividing the overall sequence management into configuration and selection phases.
Data Source
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AI summary
Sequence selection techniques for Non-Orthogonal Multiple Access (NOMA) are provided. A User Equipment (UE) sends a request to a base station, the request indicating that the UE is to conduct at least one uplink transmission. The UE receives, in response to the request, an indicator of an expected system load, a value of the indicator including a total number of sequences expected to be used at one time for uplink transmissions in the system. The UE detects that at least two different pairs of sequences in a configured set of sequences have different cross correlation values, the sequences in the set configured for scrambling uplink transmissions. The UE selects, in response to the detecting and based on the indicator, at least one sequence with an improved cross correlation with at least one other sequence the at least one sequence and the at least one other sequence to be used for scrambling uplink transmissions within the system.