Dedicated Random Access Preamble Allocation in LTE Base Stations
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Solution Overview
Problem
The existing LTE system experiences low utilization efficiency of dedicated random access preambles due to the restriction that different UEs cannot use the same preamble on different PRACH channels, leading to underutilization of available resources.
Innovation Solution
The method involves the base station allocating dedicated random access preambles and corresponding PRACH channels, with signaling providing the time and frequency domain information, allowing different UEs to use the same preamble on different PRACH channels, thereby increasing utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the base station allocates dedicated random access preambles without specifying PRACH channels, then the allocation process is simple, but the utilization efficiency of dedicated preambles is low
Solution Approach 1:
The patent segments the PRACH resource by introducing specific time domain and frequency domain parameters (subframe offset, frequency offset, PRACH configuration index). This segmentation allows different UEs to be directed to different PRACH channels, enabling the same preamble to be reused across multiple channels and thereby improving preamble utilization efficiency while maintaining allocation simplicity through parameterized signaling.
2Productivity
If the same preamble is reused across multiple PRACH channels, then preamble utilization efficiency improves, but the risk of preamble collision increases
Solution Approach 1:
The patent extends the resource dimension by introducing frequency domain offset and PRACH configuration index parameters. This multi-dimensional resource allocation allows the same preamble to be reused across different frequency channels and time configurations, increasing utilization efficiency while maintaining low collision risk through spatial and temporal separation of transmissions.
3Loss of information
If dedicated random access resource allocation is implemented without time and frequency domain parameters, then the signaling overhead is reduced, but the resource allocation flexibility is limited
Solution Approach 1:
The patent employs parameter-based resource allocation by introducing subframe offset, frequency offset, and PRACH configuration index as configurable parameters. These parameters enable flexible resource allocation adaptation to different network conditions and UE requirements while maintaining efficient signaling through compact parameter representation, achieving both low overhead and high flexibility.
Data Source
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AI summary
The present invention discloses a method and a base station for allocating the dedicated random access resource. In the method, first, the base station allocates the dedicated random access preamble to the user equipment (UE), and allocates the predetermined physical random access channel (PRACH) to which the dedicated random access preamble corresponds in the allocated radio frame; then, the base station transmits the signaling to the UE, wherein, the signaling includes the time domain information and the frequency domain information of the predetermined PRACH. The technical solution provided by the present invention can allocate the same dedicated random access preamble for different PRACH channels to different UEs, and can improve the utilization efficiency of the dedicated random access preamble.