Multi-Stage Preamble Detection for Random Access Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, such as LTE, face high latency and inefficiency in transitioning User Equipment (UE) from a standby or idle mode to an active mode due to the multi-stage preamble sequence design, which results in prolonged connection establishment times, exceeding 50 milliseconds, and is not suitable for applications requiring faster transitions.
Innovation Solution
The implementation of a multi-stage preamble detection method, where UEs transmit a first sequence associated with a group and a second sequence associated with the UE, reducing the search space and detection complexity, allowing for a 2-step contention-free random access procedure, enabling faster transitions from inactive or connected inactive modes to active modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multi-stage preamble sequence design is used for connection establishment, then the system can support multiple UE groups and reduce collision probability, but the connection establishment time increases to over 50 milliseconds
Solution Approach 1:
The patent segments the preamble detection process into two stages: first detecting a first preamble to identify UE group membership, then detecting a second preamble to identify the specific UE within the group. This segmentation allows the system to reduce collision probability by dividing the search space while maintaining faster connection establishment compared to traditional single-stage approaches.
Solution Approach 2:
The patent introduces a hierarchical dimension to preamble detection by using different preamble types at different levels: a first preamble for group-level identification and a second preamble for UE-level identification. This dimensional approach to search space reduction enables both reliability and reduced latency by organizing the detection process in multiple hierarchical levels rather than a single flat stage.
2Device complexity
If traditional single-stage preamble detection is used, then the detection process is simple, but the search space is large and detection complexity increases with more UEs
Solution Approach 1:
The patent divides the detection process into two sequential stages: first detecting a first preamble to determine UE group membership, then detecting a second preamble to identify the specific UE within the group. This segmentation reduces the search space at each stage and simplifies the overall detection process compared to a single-stage approach that would need to search through all possible UEs simultaneously.
Solution Approach 2:
The patent performs preliminary detection of the first preamble to establish UE group membership before proceeding to the second preamble detection for specific UE identification. This preliminary action filters out unnecessary search space and simplifies the subsequent detection process by narrowing down the search to only relevant UEs within the identified group.
3Speed
If a 2-step contention-free random access procedure is implemented, then transition speed from idle mode increases, but the system requires more sophisticated preamble sequence management
Solution Approach 1:
The patent segments the random access procedure into two distinct steps: first transmitting a first preamble to indicate UE group membership, then transmitting a second preamble to indicate the specific UE within the group. This segmentation enables faster mode transition by reducing the number of random access attempts needed while managing complexity through structured preamble sequence assignment and detection protocols.
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
In response to receiving a random access channel message from a User Equipment (UE), a network element in a communication network may initiate a random access procedure, for example. The random access channel message includes multiple sequences, such as a first sequence associated with a group of UEs that includes the UE and a second sequence associated with the UE, and may be in any one of multiple different message formats. The random access procedure could include respective search stages for each of the multiple sequences. Power control for random access message transmission is also implemented by the UE in some embodiments.