NOMA User Selection via Cluster Partitioning and Power Allocation
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Solution Overview
Problem
In non-orthogonal multiple access (NOMA) systems, maximizing system capacity while ensuring signal detection performance for multiple user devices is challenging, particularly in selecting user devices to optimize power allocation and interference cancellation.
Innovation Solution
A user selection method for NOMA systems involves dividing user devices into clusters, selecting reference devices, performing a power allocation algorithm to determine power factors, and adjusting cluster configurations to ensure constraints are met, thereby optimizing power allocation and interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NOMA transmission serves more user devices simultaneously, then system capacity is improved, but signal detection performance deteriorates due to increased interference
Solution Approach 1:
The patent segments user devices into multiple clusters based on channel conditions, where each cluster contains user devices with similar channel characteristics. This segmentation allows the base station to perform cluster-specific power allocation and interference management, thereby maintaining signal detection performance while serving more users simultaneously through optimized resource allocation within each segment.
2Productivity
If power allocation is optimized for system capacity, then more users can be served, but detection performance for individual users may be compromised
Solution Approach 1:
The patent implements local quality optimization by performing power allocation separately for each cluster rather than uniformly across all users. The base station determines cluster-specific power allocation factors based on the channel conditions and interference characteristics of each cluster, ensuring that users within the same cluster receive appropriately optimized power levels that maintain their detection performance while enabling the system to serve more users overall.
3Reliability
If successive interference cancellation is performed for all users, then detection performance is maintained, but system complexity increases
Solution Approach 1:
The patent reduces processing complexity by segmenting users into clusters and performing interference cancellation operations at the cluster level rather than individually for each user. The base station performs successive interference cancellation for representative users in each cluster, which significantly reduces the computational burden compared to processing all users individually, while still maintaining effective interference management and detection performance across the entire system.
Data Source
AI summary
The disclosure provides a user selection method for non-orthogonal multiple access (NOMA) systems and a base station thereof. The method includes: (1) initializing the cluster-partition parameter i to be 2; (2) dividing N user devices into i clusters; (3) selecting a reference device from each of the i clusters to form a reference cluster; (4) performing a power allocation algorithm for the reference cluster to calculate a power allocation factor for each of the reference devices; (5) determining whether each of the reference devices with the calculated power allocation factors meets a set of constraints: if all of the reference devices meet the set of constraints, increasing the value of i by 1 and then going back to step (2); if any one of the reference devices does not meet the set of constraints and i is not equal to 2, performing NOMA transmission for the reference cluster.