Random Access Preamble-DMRS Mapping for Lower Collision Uplink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face inefficiencies in random access procedures, particularly in managing preamble and demodulation reference signal (DMRS) mappings, leading to increased collision probabilities and suboptimal resource utilization during two-step random access channels.
Innovation Solution
The implementation of techniques that aggregate preamble sequences and DMRS sequences into larger groups, configuring a mapping relationship between these sequences and their corresponding time/frequency resources, allowing for one-to-one, one-to-many, or many-to-one mappings, and adapting these mappings based on pool size and resource sharing strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If preamble sequences and DMRS sequences are mapped using traditional one-to-one mapping in random access procedures, then the mapping is simple and straightforward, but the collision probability increases and resource utilization becomes suboptimal
Solution Approach 1:
The patent segments the random access procedure into distinct phases: preamble transmission phase and payload transmission phase. The preamble and payload are separated in time and can be mapped to different time-frequency resources. This segmentation allows independent optimization of each phase, reducing collision probability while maintaining manageable mapping complexity through structured resource allocation.
Solution Approach 2:
The patent introduces time as an additional dimension for resource allocation by separating preamble and payload transmissions in time. Instead of mapping preamble and payload to the same time-frequency resources, the payload is transmitted in a subsequent time slot. This dimensional separation increases the available resource space, reducing collisions while providing flexible mapping strategies for each phase.
2Productivity
If multiple preamble sequences are aggregated into larger groups for random access messages, then resource utilization improves, but the complexity of managing mappings between preambles and DMRS increases
Solution Approach 1:
The patent establishes predetermined mapping relationships between preamble sequences and payload resources in advance, before actual random access transmissions occur. The base station pre-configures which preamble sequences map to which time-frequency resources for payload transmission. This preliminary action simplifies real-time mapping management while enabling efficient aggregation of multiple preambles into larger groups, improving resource utilization without proportionally increasing complexity.
Solution Approach 2:
The patent implements dynamic mapping strategies where the mapping between preambles and DMRS sequences can be adapted based on current system conditions, traffic load, and resource availability. The base station can flexibly configure mapping relationships for different random access occasions, allowing efficient aggregation of preambles while managing complexity through adaptive rather than static mapping management.
3Reliability
If traditional random access procedures are used without separating preamble and payload transmissions, then the procedure is shorter and faster, but collision probability increases and resource efficiency decreases
Solution Approach 1:
The patent segments the random access message into distinct preamble and payload components transmitted at different times. The preamble is transmitted first to establish initial connection, followed by the payload transmission in a subsequent time slot. This segmentation improves resource efficiency by allowing separate optimization of each component's resource allocation while maintaining relatively quick access through the structured two-phase approach.
Solution Approach 2:
The patent utilizes the time dimension to separate preamble and payload transmissions, creating a temporal structure for random access. The preamble occupies one time slot while the payload occupies a subsequent time slot, allowing both components to be transmitted without resource conflicts. This time-dimensional separation improves resource efficiency while the overall procedure remains efficient through the streamlined two-phase structure.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods, systems, and devices for wireless communications are described. A base station may determine a relationship between preamble sequences of a preamble portion of a random access message and resources for demodulation reference signal (DMRS) sequences and physical uplink shared channel (PUSCH) occasions of a payload portion of a random access message. The base station may map some preamble sequences to some of the DMRS sequences and PUSCH payloads within a mapping period. The base station may transmit, to a user equipment (UE), an indication of the mapping rule between the preamble sequences and the DMRS sequences and payloads. The UE may transmit, based on determining the relationship, at least one preamble sequence in a preamble occasion and at least one DMRS sequence and one payload of the random access message in a PUSCH occasion based on the configured mapping rule.