Enhanced PUCCH Contention Feedback for Low-Latency LTE Uplink Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3GPP LTE networks face significant latency issues during uplink access due to contention and collisions on the random access channel, leading to lengthy delays in resource allocation requests.
Innovation Solution
The proposed solution involves the UE transmitting a contention sequence on the enhanced physical uplink control channel (PUCCH) and data on the physical uplink shared channel (PUSCH) concurrently, with the eNB allocating resources for uplink resource allocation without a traditional uplink grant, allowing for reduced latency and improved resource management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the conventional RACH procedure is used for uplink resource allocation requests, then the procedure is simple and standardized, but latency is significantly increased due to contention and collisions
Solution Approach 1:
The UE transmits a contention sequence on the enhanced PUCCH before actual data transmission, establishing a preliminary reservation of uplink resources. This preliminary action allows the eNB to allocate resources in advance without waiting for the traditional RACH procedure, thereby reducing latency while maintaining manageable complexity through structured resource allocation patterns
Solution Approach 2:
The patent introduces an intermediary mechanism where the contention sequence on enhanced PUCCH acts as a mediator between the UE's resource allocation request and the eNB's grant. This intermediary channel allows direct communication of resource requests without going through the contention-based RACH procedure, reducing latency while the eNB maintains control over resource allocation to manage system complexity
2Productivity
If concurrent transmissions on PUCCH and PUSCH are allowed, then resource allocation efficiency is improved and latency is reduced, but interference management and signal quality become more difficult to control
Solution Approach 1:
The patent segments the uplink transmission into distinct components: contention sequence on enhanced PUCCH and data on PUSCH. This segmentation allows independent optimization and protection of each channel, with the contention sequence carrying critical resource allocation requests that can be reliably detected even in the presence of concurrent transmissions, thereby maintaining signal quality while improving resource allocation efficiency
Solution Approach 2:
The patent applies local quality by assigning specific formats and resource allocations to the contention sequence on enhanced PUCCH that are optimized for reliable detection. The eNB is configured to specifically detect these contention sequences with appropriate signal processing parameters, ensuring high reliability for the critical resource allocation function while allowing concurrent PUSCH transmissions for data
Data Source
AI summary
Methods for contention-based transmission with contention-free feedback for reduced latency in LTE Advanced networks and an enhanced PUCCH are generally disclosed herein. User equipment (UE) may transmit a contention sequence on a physical uplink control channel (PUCCH) to an enhanced-Node B (eNB) and may concurrently transmit data requesting uplink resources on a physical uplink shared channel (PUSCH) to the eNB. The contention sequence is transmitted on the PUCCH in accordance with a format that is assigned by the eNB. The contention sequence is either randomly selected by the UE or assigned by the eNB. When the contention sequence and data are not successfully received by the eNB, the UE may fall back to a more conventional random access channel (RACH) procedure for uplink resource allocation.