Partial Collision Multiple Access for Wireless Networks
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Solution Overview
Problem
Existing unscheduled data transmission methods in wireless networks, such as SCMA, require complex decoding algorithms and incur high latency and power consumption due to scheduling overhead, especially in machine-type communications where low data rates are sufficient, leading to inefficient resource usage.
Innovation Solution
The implementation of a Partial Collision Multiple Access (PCMA) scheme, which uses predefined sequence patterns to generate spreading sequences that allow for partial collisions, enabling efficient unscheduled data transmissions by avoiding full sequence collisions and utilizing simpler decoding methods like successive interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If SCMA encoding is used for unscheduled transmissions, then data transmission efficiency is improved, but decoding complexity and power consumption increase
Solution Approach 1:
The patent segments the codebook into multiple subsets, each corresponding to a specific number of active resources. This segmentation allows the receiver to identify and decode only the relevant subset based on the detected number of active resources, significantly reducing decoding complexity while maintaining transmission efficiency
Solution Approach 2:
The patent employs partial collisions where sequences from different users may overlap on some resources but not all. This partial action approach allows efficient detection and decoding by focusing on the specific collision patterns rather than requiring complete sequence separation, reducing the computational burden
2Productivity
If scheduled transmissions are used, then resource allocation efficiency is improved, but latency and overhead increase
Solution Approach 1:
The patent pre-assigns codebook subsets to different numbers of active resources in advance. When transmissions occur, the system can immediately identify which subset to use based on the pre-configured mapping, eliminating the need for real-time scheduling decisions and reducing latency while maintaining efficient resource allocation
Solution Approach 2:
The system enables self-service by allowing receivers to autonomously determine the number of active resources and select the appropriate codebook subset without requiring scheduling grants or control messages. This self-service mechanism eliminates scheduling overhead and reduces latency while maintaining resource allocation efficiency
3Reliability
If full sequence collision avoidance is implemented, then transmission reliability is improved, but resource utilization decreases
Solution Approach 1:
The patent allows partial collisions where sequences may overlap on some resources but maintains orthogonality on others. This selective collision approach enables better resource utilization by allowing overlapping transmissions while preserving transmission reliability through orthogonal components that can be reliably detected and decoded
Solution Approach 2:
The patent applies different collision properties to different resources within the same transmission. Some resources are designed for orthogonal separation while others allow controlled partial collisions. This local differentiation optimizes both reliability (through orthogonal resources) and resource utilization (through partial collision resources)
Data Source
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AI summary
Methods, devices and systems for encoding and transmitting data in a wireless communications system and, in particular, for unscheduled data transmissions including low data rate transmissions. The method for transmitting data in a wireless network includes mapping data according to a predefined sequence pattern from a group of sequence patterns to provide a spreading sequence that includes multiple non-zero elements and that is enabled to partially collide in the wireless network with other spreading sequences that have been mapped according to other sequence patterns from the group； and transmitting the spreading sequence. Multiple sequences may be received by a network node and decoded using successive interference cancellation (SIC) techniques.