NPRACH Preamble Transmission for Extended NB-IoT Cell Radius
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Solution Overview
Problem
Current wireless communication systems face challenges in effectively performing random access procedures, particularly in supporting an extended cell radius for narrowband Internet of Things (NB-IoT) communication, where existing technologies struggle to ensure reliable transmission and reception of random access preambles.
Innovation Solution
A method and apparatus for performing a random access procedure in a wireless communication system, involving the reception of narrowband physical random access channel (NPRACH) configuration information and repeated transmission of NPRACH preambles, where the last repeated transmission is dropped or punctured if the time gap between transmissions is less than the guard time, with options for configuring guard time and number of repetitions through NPRACH configuration information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the number of NPRACH preamble repetitions is increased to extend cell radius, then coverage range is improved, but transmission time and processing complexity increase
Solution Approach 1:
The patent applies partial action by transmitting NPRACH preambles multiple times (1, 2, or 4 repetitions) rather than continuous transmission. This allows the system to achieve extended coverage through selective repeated transmissions while controlling overall transmission time. The base station can configure the number of repetitions based on coverage requirements, performing only the necessary number of transmissions to achieve reliable detection.
2Reliability
If guard time is increased to accommodate extended cell radius, then transmission reliability is improved, but available transmission time for data reduces
Solution Approach 1:
The patent implements dynamic guard time configuration where the guard time duration is adjusted based on the actual cell radius and propagation delay requirements. Instead of using a fixed guard time, the system dynamically sets the guard time to be sufficient for the extended cell radius while minimizing overhead. This allows the system to adapt the guard time to specific deployment scenarios, ensuring reliability without excessive time consumption.
3Adaptability or versatility
If NPRACH configuration is made flexible to support extended cell radius, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent achieves universality by designing a configurable NPRACH transmission framework that can adapt to different cell radii and coverage requirements through a unified configuration mechanism. The base station provides NPRACH configuration information including number of repetitions and guard time settings that work across various deployment scenarios. This universal configuration approach allows the same system to serve both normal and extended cell radius cases without requiring separate specialized mechanisms.
Data Source
AI summary
The present invention relates to a method for performing a random access process in a wireless communication system, and a device therefor, and relates to a method and a device therefor, the method comprising the steps of: receiving, from a base station, narrowband physical random access channel (NPRACH) configuration information; and repeatedly transmitting an NPRACH preamble on the basis of the received NPRACH configuration information, wherein, if a time gap between a completion time point of the last repeated transmission of the NPRACH preamble and a next subframe is smaller than a guard time, the last repeated transmission of the NPRACH preamble is dropped, or is punctured as much as the difference between the guard time and the time gap in the last repeated transmission of the NPRACH preamble.