Random Access Channel Resource Allocation for Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE and LTE-A cellular networks, the random access channel (RACH) procedure faces challenges with resource waste and increased processing complexity due to ambiguity in downlink component carrier identification during asymmetric carrier aggregation, leading to inefficient resource usage and potential collisions.
Innovation Solution
The method involves grouping preamble signatures into distinct groups corresponding to downlink component carriers and assigning configuration data to each group, allowing the eNodeB to identify the correct downlink carrier through preamble signature detection, thereby reducing resource waste and maintaining backward compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If asymmetric carrier aggregation is implemented to increase system capacity and flexibility, then network capacity and service availability are improved, but ambiguity in downlink component carrier identification occurs leading to resource waste and increased processing complexity
Solution Approach 1:
The patent segments the preamble signature resources by creating separate signature groups for each downlink component carrier. This segmentation allows the eNodeB to identify which specific downlink carrier a UE is camped on by detecting the preamble signature from the corresponding group, thereby resolving the ambiguity issue while maintaining asymmetric carrier aggregation benefits
Solution Approach 2:
The patent introduces an intermediary mechanism - the grouped preamble signature structure - that mediates between the UE's random access attempt and the eNodeB's carrier identification. By organizing preambles into carrier-specific groups and using group indicators, the system enables accurate carrier identification without requiring complex processing at the eNodeB
2Adaptability or versatility
If asymmetric carrier aggregation is implemented, then flexible use of frequency bands is improved, but resource waste occurs due to incorrect downlink carrier identification
Solution Approach 1:
By segmenting preamble signatures into distinct groups associated with each downlink component carrier, the patent ensures that UEs select preambles from the correct group corresponding to their camped carrier. This prevents resource waste caused by UEs attempting access on wrong carriers while maintaining flexible frequency band utilization through asymmetric aggregation
3Device complexity
If traditional RACH procedure is used without preamble grouping, then device complexity is reduced, but downlink carrier identification accuracy deteriorates leading to collisions and resource waste
Solution Approach 1:
The patent applies preliminary action by pre-organizing preamble signatures into carrier-specific groups before the random access procedure begins. The eNodeB configures and broadcasts the grouped preamble structure in advance, so that when UEs perform random access, they can efficiently identify the correct downlink carrier through the group indicator without requiring complex real-time analysis, thus maintaining simplicity while improving accuracy
Data Source
AI summary
The present invention provides a method of configuring random access resources for random access transmission, the method comprising: determining a number n of preamble signatures that can be used for random access transmission; grouping the n preamble signatures into K groups j (j=1,2...K) wherein K corresponds to a number of downlink component carriers and K is greater than or equal to 2; assigning each group j to a respective downlink component carrier; assigning configuration data to each group j; and transmitting the group j configuration data on the corresponding downlink component carrier.