Scheduling Request Resource Assignment for LTE Access Latency
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Solution Overview
Problem
Current LTE systems face challenges in managing scheduling requests due to increased connected-mode user populations, leading to high access latency and inefficient use of uplink resources, as existing scheduling request approaches either result in excessive resource reservation or degraded latency.
Innovation Solution
Implementing a method that assigns a common or shared scheduling request resource to multiple users, using existing PUCCH formats to efficiently convey user IDs and reduce the need for physical layer redesign, allowing for low-latency access and improved resource utilization through orthogonal multiple access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If dedicated scheduling request resources are reserved for each user, then access latency is reduced, but resource utilization deteriorates due to excessive resource reservation
Solution Approach 1:
The patent merges multiple users' scheduling request resources into a shared common resource pool. Instead of allocating dedicated resources to each user, multiple users share the same uplink resources (PUCCH or PUSCH) for sending scheduling requests, which reduces resource reservation overhead while maintaining low access latency through orthogonal multiple access techniques.
Solution Approach 2:
The patent makes uplink resources universal by allowing them to serve multiple functions and multiple users simultaneously. The same uplink resources can be used by different users for scheduling requests at different times or with different orthogonal codes, increasing resource utilization efficiency while maintaining system performance.
2Loss of energy
If common scheduling request resources are shared among multiple users, then resource utilization is improved, but access latency worsens due to resource contention
Solution Approach 1:
The patent segments the common scheduling request resources into multiple orthogonal sub-resources using different orthogonal codes, cyclic shifts, or time-frequency partitions. This segmentation allows multiple users to access the shared resource pool simultaneously without collision, maintaining low access latency while improving overall resource utilization through efficient multiplexing.
Solution Approach 2:
The patent implements dynamic resource allocation where users can dynamically select from available orthogonal resources in the common pool based on current system conditions. The eNodeB can dynamically adjust the orthogonal resource assignments and manage the shared resource pool to optimize both access latency and resource utilization in real-time.
3Device complexity
If existing PUCCH formats are used for common scheduling requests, then device complexity is reduced, but measurement precision deteriorates due to format limitations
Solution Approach 1:
The patent extends the capability of existing PUCCH formats by utilizing additional dimensions such as cyclic shifts, orthogonal cover codes, or time-frequency resource selections to encode user ID information. This allows existing formats to convey more information (user IDs) without requiring new physical layer formats, maintaining low device complexity while improving detection precision through increased dimensional separation.
Data Source
AI summary
In some implementations, a method implemented in a user equipment UE for single carrier frequency division multiple access SC-FDMA within a wireless system includes receiving an assignment of a plurality of uplink scheduling request resources and comprising a plurality of SC-FDMA subcarriers of the wireless system. One of the plurality of uplink scheduling request resources is selected for transmission of scheduling requests. It is determined that a change in uplink scheduling request resource should be made. Upon determining that a change in scheduling request resource should be made, another of the assigned uplink scheduling request resources is selected for transmission of scheduling requests.