PRACH Resource Allocation in 5G NR Random Access
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Solution Overview
Problem
In the 5G NR radio communication system, there is a lack of a defined method to appropriately indicate a PRACH resource for multiple user apparatuses during the initial access procedure, which can lead to resource contention and depletion.
Innovation Solution
A user apparatus is equipped with a reception unit to receive information specifying an available random access channel, a control unit to identify the resource in the time or frequency domain, and a transmission unit to transmit a random access preamble using the identified resource, allowing for efficient allocation of PRACH resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual PRACH resources are allocated to multiple user apparatuses, then resource contention is avoided, but the complexity of resource indication increases
Solution Approach 1:
The PRACH resource indication is segmented into two parts: a common RACH occasion indicator that applies to multiple user apparatuses, and a user-specific preamble indicator. This segmentation allows efficient resource allocation by avoiding redundant transmission of common resource information while maintaining individual resource assignment for each user apparatus.
Solution Approach 2:
Instead of indicating complete PRACH resources (time/frequency/preamble) individually to each user apparatus, the patent inverts the approach by indicating only the preamble sequence individually while using a common indication for the RACH occasion. This reduces the overall indication complexity while maintaining individual resource allocation.
2Quantity of substance
If PRACH resources are allocated in the time domain, then frequency resources are preserved, but time resource consumption increases
Solution Approach 1:
The patent enables dynamic selection between time-domain and frequency-domain PRACH resource allocation based on system conditions and user apparatus requirements. The base station can flexibly configure PRACH resources in either domain, allowing optimization of resource utilization according to current network load and interference conditions.
3Loss of time
If PRACH resources are allocated in the frequency domain, then time resources are preserved, but frequency resource consumption increases
Solution Approach 1:
The system supports dynamic configuration of PRACH resources in either time or frequency domain, allowing the base station to adapt resource allocation strategy based on available resources and service requirements. This dynamic approach enables optimization of the trade-off between time and frequency resource consumption.
Data Source
AI summary
A user apparatus receives an instruction to execute a random access procedure from a base station apparatus and includes a reception unit that receives first information specifying an available random access channel from the base station apparatus; a control unit that identifies, on the basis of the first information, a resource of the available random access channel in a time domain or a frequency domain; and a transmission unit that transmits a random access preamble using the identified resource.