Adaptive Random Access Repetition for CE-MTC UEs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in efficiently supporting Coverage Enhanced Machine Type Communication User Equipments (CE-MTC UEs) due to high penetration losses, leading to significant degradation in spectral efficiency and resource wastage in random access procedures, as existing methods require numerous repetitions without optimal repetition level adaptation.
Innovation Solution
The method involves a base station and user equipment that adaptively use repetition levels for random access messages, with the base station receiving and responding with messages having characteristics dependent on a first repetition level, allowing for efficient resource allocation and reduced repetitions for UEs with better radio conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If numerous repetitions are used for random access messages to ensure reliable delivery to CE-MTC UEs, then communication reliability is improved, but spectral efficiency deteriorates
Solution Approach 1:
The patent applies local quality by configuring different repetition levels for different messages in the random access procedure. Specifically, message 1 (preamble) uses a first repetition level, while message 2 (RAR) and subsequent messages use a second repetition level that is lower than the first. This allows each message to have the appropriate repetition level for its specific requirements, improving overall spectral efficiency while maintaining necessary reliability for each message type.
Solution Approach 2:
The patent implements dynamics by making the repetition level adaptive rather than fixed. The base station determines the repetition level for each message based on the detected repetition level of previous messages. This dynamic adjustment allows the system to optimize the number of repetitions based on actual channel conditions and message types, preventing unnecessary repetitions and improving spectral efficiency.
2Reliability
If a single high repetition level is used to target CE-MTC UEs with worst radio conditions, then coverage is improved, but resource consumption increases
Solution Approach 1:
The patent applies local quality by assigning different repetition levels to different messages based on their specific requirements. Message 1 uses a higher first repetition level to ensure detection, while messages 2 and 3 use a lower second repetition level. This localized optimization ensures coverage for worst-case scenarios while reducing resource consumption for messages that require fewer repetitions.
Solution Approach 2:
The patent applies partial action by using excessive repetitions (first repetition level) only for the critical message 1 transmission, and then reducing to partial repetitions (second repetition level) for subsequent messages. This ensures that the maximum necessary repetitions are used only where absolutely required, while reducing overall resource consumption.
Data Source
AI summary
One embodiment of the present disclosure relates to a method for random access in a base station supporting communication with at least one CE-MTC UE. The method comprises: receiving from a user equipment, repetition transmissions of a first message including a random access preamble; repeatedly transmitting to the user equipment a second message including a random access response, RAR, wherein the second message has a characteristic dependent upon a first repetition level. Another embodiment of the present invention also relates to corresponding method for random access in a user equipment. According to an aspect of the present disclosure, there are provided corresponding devices.