5G PRACH Time-Shift Configuration for Sector Interference Reduction
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Solution Overview
Problem
Existing 5G PRACH configurations face interference and preamble collision issues due to the use of the same root sequence index across sectors, leading to decreased preamble success rates and increased latency.
Innovation Solution
Implementing a PRACH configuration system that utilizes the same root sequence index across sectors but employs time or frequency shifts for each preamble to arrive at different times or frequencies, reducing interference and collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same root sequence index is used across sectors, then configuration simplicity is improved, but PRACH interference increases and preamble success rate decreases
Solution Approach 1:
The patent introduces time domain shifts as an additional dimension to differentiate preambles across sectors. Instead of using different root sequence indices (one-dimensional differentiation), the system applies time shifts to spread preambles across different time resources, enabling sector differentiation while maintaining the same root sequence index and reducing interference.
Solution Approach 2:
The patent changes the time domain parameter (time shift value) for each sector while keeping the root sequence index constant. This parameter change allows the system to maintain configuration simplicity while effectively separating preambles from different sectors in the time domain, thereby reducing interference and improving preamble success rate.
2Reliability
If time shifts are applied to separate preambles, then interference is reduced, but configuration complexity increases
Solution Approach 1:
The patent modifies existing PRACH configuration parameters by introducing time shift values for different sectors. This approach leverages the existing PRACH framework and extends it with time domain differentiation, achieving improved PRACH performance while maintaining a relatively simple configuration structure that builds upon standard 5G NR parameters.
3Loss of time
If preambles are transmitted at the same time, then latency is reduced, but preamble collisions increase
Solution Approach 1:
The patent transitions from simultaneous preamble transmission (time-agnostic approach) to time-differentiated transmission by introducing time shifts. This dimensional change in the time domain allows preambles to be separated in time, reducing collisions while managing latency through controlled time distribution across sectors.
Solution Approach 2:
The patent segments the preamble transmission resources in the time domain by applying different time shifts to different sectors. This segmentation divides the previously simultaneous transmission into separated time slots, reducing preamble collisions while maintaining efficient access through structured time distribution.
Data Source
AI summary
Systems and methods for enhanced PRACH 5G configuration by preventing interference with signal transmission. One such method includes: implementing a PRACH configuration in which the same root sequence index (RSI) is utilized across the sectors of the site, implementing the PRACH configuration in which a time shift is utilized for each preamble that provides each preamble with its own time slot, enabling multiple UEs to each send a preamble that is time shifted to arrive at the gNB at different times and avoid a RAPID (Random Access Preamble Identifier) mismatch, and receiving preambles that are frequency shifted and reducing PRACH interference among different sectors that causes a degradation of PRACH performance using shifts in time domain.