SCMA Resource Allocation via Asynchronous Group Segmentation
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Solution Overview
Problem
In sparse code multiple access (SCMA) systems, synchronizing signals from multiple devices at a base station is resource-intensive and increases overhead, especially as the number of devices grows, due to the need for global synchronization.
Innovation Solution
The method involves partitioning a resource block into multiple resource regions and assigning these regions to device groups, allowing asynchronous SCMA transmissions, which reduces the need for synchronization and mitigates inter-resource region interference using digital filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If global synchronization is implemented for SCMA signals from multiple devices, then signal reception accuracy is improved, but signaling overhead and system complexity increase
Solution Approach 1:
The patent divides devices into multiple groups, where each group performs synchronous transmission within the group but different groups perform asynchronous transmission relative to each other. This segmentation reduces the need for global synchronization signaling while maintaining reception accuracy within each group through localized synchronization.
2Quantity of substance
If the number of connected devices is increased in SCMA systems, then system capacity is improved, but collision probability and interference increase
Solution Approach 1:
Devices are segmented into multiple groups that transmit asynchronously relative to each other. This reduces collision probability because devices in different groups do not contend for the same time-frequency resources simultaneously, allowing the system to support more connected devices overall.
Solution Approach 2:
The patent introduces a group dimension in addition to individual device dimensions. By organizing devices into groups with different timing references, the system adds a temporal dimension for resource separation, enabling more devices to be supported without increasing collision probability.
3Loss of information
If asynchronous transmissions are allowed from different device groups, then signaling overhead is reduced, but inter-resource region interference increases
Solution Approach 1:
The patent changes the timing parameter for different device groups, assigning different time offsets to each group. This allows asynchronous transmissions that reduce synchronization overhead while managing interference through controlled parameter differentiation across groups.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces signaling overhead and allows for efficient asynchronous SCMA signal reception by eliminating the requirement for global synchronization, improving scalability and reducing interference between device groups.
Implementation Method 1
The mixer is coupled to the antenna and configured to convert the asynchronous SCMA signals from a radio frequency to a baseband frequency
Implementation Method 2
The plurality of filters are coupled to the mixer and respectively correspond to the plurality of resource regions. The plurality of filters are also configured to filter inter-resource region interference for each of the plurality of resource regions
Data Source
AI summary
An embodiment method of resource allocation for sparse code multiple access (SCMA) transmissions includes partitioning a resource block into a plurality of resource regions. The method also includes assigning the plurality of resource regions to respective device groups. The resource region assignments are then signaled to devices of the respective device groups. The method also includes receiving SCMA signals from the devices of the respective device groups. The SCMA signals from one group of the respective device groups are asynchronous with respect to the SCMA signals from another group of the respective device groups.