Dynamic MA Signature Selection for NOMA Interference
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Solution Overview
Problem
Current wireless communication systems face challenges in managing traffic load dynamics, leading to increased multi-user interference and reduced spectral efficiency in grant-free contention-based non-orthogonal multiple access (NOMA) transmissions, particularly in 5G communication systems.
Innovation Solution
The base station calculates and communicates traffic load statistics to user equipment (UE), allowing for adaptive selection of multiple access (MA) signatures from predefined pools based on current traffic conditions, optimizing cross-correlation properties to reduce interference and enhance network capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If grant-free contention-based NOMA transmissions are used to increase network capacity, then productivity is improved, but multi-user interference increases causing spectral efficiency to deteriorate
Solution Approach 1:
The patent implements dynamic MA signature selection where the base station adapts the MA signature pool size and composition based on real-time traffic load conditions. During high traffic periods, a larger pool with optimized cross-correlation properties is used to accommodate more users while controlling interference. During low traffic periods, a smaller pool is used to maintain high spectral efficiency. This dynamic adaptation resolves the contradiction between maximizing network capacity and maintaining spectral efficiency.
Solution Approach 2:
The system changes key parameters of the MA signatures including the pool size, signature length, and cross-correlation properties based on traffic load statistics. The base station configures different MA signature pools with varying parameters and selects appropriate pools dynamically. This parameter adaptation allows the system to optimize the trade-off between supporting more simultaneous users (productivity) and maintaining signal quality (spectral efficiency).
2Reliability
If adaptive MA signature selection is implemented to reduce multi-user interference, then spectral efficiency is improved, but device complexity increases
Solution Approach 1:
The base station pre-generates and stores multiple MA signature pools with different configurations and optimized cross-correlation properties. These pools are prepared in advance based on expected traffic conditions. When traffic load changes, the base station simply selects from the pre-prepared pools rather than generating new signatures dynamically. This preliminary preparation reduces the real-time computational complexity while maintaining the ability to adapt to traffic conditions.
Solution Approach 2:
The system manages complexity by parameterizing the MA signature pools and using systematic methods to generate them. The base station configures pools with specific parameters (size, length, correlation properties) that can be adjusted based on traffic load. This parameter-based approach simplifies the management and selection process compared to designing custom signatures for each condition, reducing device complexity while maintaining spectral efficiency.
Data Source
AI summary
Optimizing the resource configuration or selection for grant-free contention-based non-orthogonal multiple access (NOMA) transmissions is an effective way to increase network capacity and reduce multi-user interference at the user equipment (UE). In some embodiments, a network node may determine the current traffic load, select multiple access (MA) sequences for the UE based on the determination, and transmit this selection to the UE for subsequent transmissions. In other embodiments, the UE may receive a message with an indication of the traffic load being experienced by the base station that the UE is attempting to connect to, and then may randomly select an MA sequence for subsequent transmissions.