Interleaver-Based PRACH Preamble Sequence Generation
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Solution Overview
Problem
The 5G network requires higher PRACH capacity to support a larger number of users, but the limited number of preamble sequences available in the Physical Random Access Channel (PRACH) leads to reduced access success rates, affecting user experience.
Innovation Solution
An interleaver-based method and apparatus that generates multiple different preamble sequences from a limited set by using multiple interleavers, allowing more terminal devices to access the base station without interference, thereby increasing PRACH capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of preamble sequences in the PRACH is increased to support more users, then the PRACH capacity is improved, but the limited space of the PRACH prevents further expansion
Solution Approach 1:
The patent divides the limited PRACH space into multiple resource blocks, allowing preamble sequences to be distributed across different frequency and time resources. This segmentation enables more preamble sequences to coexist within the constrained physical space by utilizing the multi-dimensional resource structure of the PRACH.
Solution Approach 2:
The patent extends the PRACH capacity by utilizing multiple dimensions including frequency resources (different resource blocks), time resources (different slots), and spatial resources (multiple antennas). This dimensional expansion allows the system to generate more distinct preamble sequences without increasing the fundamental PRACH space, effectively resolving the capacity limitation.
2Quantity of substance
If the same preamble sequence is reused by multiple terminal devices, then the PRACH capacity is increased, but correlation detection fails due to strong correlation between identical sequences
Solution Approach 1:
The patent applies interleaving operations that modify the parameters of preamble sequences by permuting their elements according to different interleaving patterns. This parameter transformation ensures that even when the same base preamble sequence is reused, the resulting interleaved sequences have sufficiently different correlation characteristics, allowing reliable detection and differentiation at the base station.
Solution Approach 2:
The patent introduces interleaving operations as an intermediary transformation layer between the original preamble sequences and the transmitted signals. This intermediary process modifies the sequences to reduce correlation while preserving the ability to recover the original information, effectively mediating between sequence reuse and detection reliability.
Data Source
AI summary
The embodiments of the present invention provide an interleave-based method and apparatus for enhancing capacity of a random access channel, wherein the method is applied to a terminal device. The method includes: receiving a set of preamble sequences and at least two interleavers sent by a base station; determining, when a random access is triggered, a to-be-used preamble sequence from the set of preamble sequences as a target preamble sequence, and randomly determining a to-be-used interleaver from the at least two interleavers as a target interleaver; performing interleaving processing on the target preamble sequence by using the target interleaver to generate an interleaved target preamble sequence, wherein, performing interleaving processing on the same preamble sequence by using different interleavers will generate different interleaved preamble sequences; sending a random access request to the base station by using the interleaved target preamble sequence. Applying the embodiments of the present invention can increase the number of available preamble sequences and increase the capacity of the PRACH.