NPRACH Frequency Hopping for Interference Reduction
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Solution Overview
Problem
Current wireless communication systems face challenges in effectively enhancing the range of random access procedures and minimizing interference between preambles with different formats and those with the same format, particularly in next-generation communication systems requiring improved mobile broadband and massive machine-type communications.
Innovation Solution
The method involves efficient frequency hopping and resource mapping between legacy and enhanced preambles, including extended cyclic prefix durations and narrowed subcarrier spacings, to support larger cell radii and reduce interference, while allowing coexistence of legacy and enhanced preambles within the same NPRACH resource configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If frequency hopping is performed between random access preambles, then interference between preambles with different formats and same format is reduced, but frequency resource allocation complexity increases
Solution Approach 1:
The NPRACH frequency resources are divided into multiple frequency regions, with each region assigned to specific preamble formats. This segmentation allows legacy preambles and enhanced preambles to operate in separate frequency regions, reducing mutual interference while simplifying the frequency hopping mechanism within each region.
Solution Approach 2:
The patent pre-configures frequency region mappings for different preamble formats before random access occurs. The UE is provided with configuration information that indicates which frequency regions correspond to which preamble formats, allowing the UE to select appropriate frequency resources in advance without complex real-time calculations.
2Length of stationary object
If extended cyclic prefix durations and narrowed subcarrier spacings are used, then support for larger cell radii is improved, but resource allocation efficiency decreases
Solution Approach 1:
The patent applies different cyclic prefix durations and subcarrier spacings locally to different frequency regions based on the preamble format. Enhanced preambles use extended cyclic prefix and narrowed subcarrier spacing in their designated frequency regions to support larger cell radii, while legacy preambles maintain standard parameters in their regions, preserving overall resource allocation efficiency.
Solution Approach 2:
The patent introduces frequency region as an additional dimension for resource allocation. By mapping different preamble formats to different frequency regions, the system can apply different physical layer parameters (cyclic prefix duration, subcarrier spacing) in different frequency dimensions, enabling support for both large and small cell radii simultaneously without compromising overall system efficiency.
3Adaptability or versatility
If legacy and enhanced preambles coexist in the same NPRACH resource configuration, then system compatibility is improved, but interference between different preamble formats increases
Solution Approach 1:
The NPRACH resources are segmented into multiple frequency regions, with each region dedicated to specific preamble formats. Legacy preambles are allocated to certain frequency regions while enhanced preambles are allocated to other frequency regions. This segmentation enables coexistence of different preamble formats in the same NPRACH configuration while minimizing mutual interference through frequency isolation.
Data Source
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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, more specifically, to a method and a device therefor, the method comprising the steps of: receiving narrowband physical random access channel (NPRACH) configuration information; and transmitting a random access preamble on the basis of the received NPRACH configuration information, wherein a sub-carrier spacing for the random access preamble is set to 3.75/N kHz, where N is an integer greater than or equal to 3, the random access preamble includes multiple symbol groups, the multiple symbol groups are transmitted on the basis of frequency-hopping, and a frequency-hopping distance between each of the multiple symbol groups includes a value between 3.75/N kHz and 6∗3.75 kHz.