PRACH Frequency Domain Mapping for Wireless Random Access
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in the random access procedure, particularly in the use of physical random access channels (PRACH) in frequency-domain mapping, which affects the performance and coverage in unlicensed bands.
Innovation Solution
The method involves configuring the PRACH sequence by repeatedly mapping it in the frequency domain across 12 consecutive physical resource blocks (PRBs) with specific zero padding and using different root indices and cyclic shifts, optimizing the frequency-domain locations based on subcarrier spacing to enhance resource allocation and channel access efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PRACH sequence is repeatedly mapped in frequency domain across 12 consecutive PRBs, then random access procedure efficiency is improved, but device complexity increases
Solution Approach 1:
The PRACH sequence is segmented and repeatedly mapped across multiple frequency resources (12 consecutive PRBs). Each repetition occupies a specific frequency range, dividing the overall frequency domain into manageable segments that can be independently processed and transmitted
Solution Approach 2:
The patent transitions from traditional time-domain or single-frequency PRACH mapping to multi-dimensional frequency domain mapping. By repeating the sequence across 12 consecutive PRBs in the frequency domain, the system exploits frequency diversity and enables more efficient random access procedures through enhanced signal detection capabilities
2Productivity
If different root indices and cyclic shifts are used for PRACH sequences, then channel access efficiency is improved, but signal processing complexity increases
Solution Approach 1:
Different root indices and cyclic shifts are applied to different PRACH sequences mapped in the frequency domain. This local differentiation allows multiple UEs to access the channel simultaneously with distinct sequence characteristics, improving channel access efficiency while maintaining manageable processing complexity through structured variation
Solution Approach 2:
The patent varies key sequence parameters (root indices and cyclic shifts) to generate diverse PRACH sequences. By changing these parameters across different frequency-mapped sequences, the system enables efficient channel access for multiple users while the structured parameter variation keeps processing complexity manageable
3Reliability
If PRACH is optimized for unlicensed bands, then coverage and capacity are improved, but compatibility with existing systems becomes more difficult
Solution Approach 1:
The frequency domain repeated mapping approach is designed to be universally applicable across different band types (licensed and unlicensed). The same fundamental mapping structure can be adapted to various frequency ranges and system configurations, maintaining compatibility while optimizing performance for unlicensed band characteristics
Data Source
AI summary
A method and an apparatus for transmitting and receiving signals in a wireless communication system according to one embodiment of the present invention comprises transmitting a first physical random access channel (PRACH), and receiving a random access response (RAR) on the basis thereof, wherein the first PRACH may be configured by a PRACH sequence of a particular length, which is mapped to 12 consecutive physical resource blocks (PRBs), being repetitively mapped multiple times in the frequency domain.