RACH Preamble OFDM Boundary Alignment for Wireless Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing number of user equipment (UEs) and data/control information to be transmitted by base stations in wireless communication systems poses a challenge due to limited resources, necessitating efficient methods for uplink/downlink data and control information transmission while reducing latency and supporting high-frequency bands.
Innovation Solution
A method for transmitting and receiving a random access channel (RACH) preamble using orthogonal frequency division multiplexing (OFDM) symbols, with a sequence part and cyclic prefix, optimized for efficient resource utilization and latency reduction, applicable in wireless communication systems employing new radio access technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of user equipments and data/control information to be transmitted increases, then the communication capacity and service coverage are improved, but the limited radio resources become insufficient and transmission efficiency decreases
Solution Approach 1:
The random access preamble is segmented into multiple parts: a sequence part with length NSEQ and a cyclic prefix part with length NCP,RA. This segmentation allows the preamble to be transmitted using multiple OFDM symbols (n symbols), where n = NSEQ/Nu, enabling more efficient use of limited radio resources by distributing the preamble transmission across multiple symbol periods rather than requiring a single long symbol.
Solution Approach 2:
The patent transitions from traditional single-carrier preamble transmission to OFDM-based multi-symbol preamble transmission. By introducing the cyclic prefix and extending the preamble across multiple OFDM symbols, the solution adds a temporal dimension to the transmission, allowing the base station to receive preambles from multiple user equipments more efficiently within the limited radio resource region.
2Productivity
If traditional random access preamble transmission is used, then the transmission format is simple, but the latency and throughput are insufficient for modern wireless communication requirements
Solution Approach 1:
The patent changes the key parameters of the random access preamble transmission: it specifies the preamble length NRA as equal to the total length of OFDM symbols (n × Nu + NCP,RA), defines the sequence part length NSEQ as Nu × n, and sets the cyclic prefix length NCP,RA. These parameter changes enable the preamble to utilize multiple OFDM symbols efficiently, thereby improving throughput and reducing latency while maintaining a structured and manageable transmission format.
3Productivity
If more OFDM symbols are used for preamble transmission, then the resource utilization efficiency is improved, but the transmission time and processing complexity increase
Solution Approach 1:
The patent ensures continuous and efficient use of radio resources by transmitting the preamble across multiple OFDM symbols without idle gaps. The sequence part and cyclic prefix part are continuously transmitted in the time domain, allowing the base station to receive preambles from multiple user equipments back-to-back, thereby improving resource utilization efficiency while minimizing overall transmission time through continuous operation.
Data Source
AI summary
A UE transmits a random access channel (RACH) preamble and a BS receives the RACH channel. The BS configures the RACH preamble to align boundaries of the RACH preamble with boundaries of OFDM symbols on which the RACH preamble is configured in the time domain. The UE generates/transmits the RACH preamble to align the boundaries of the RACH preamble with the boundaries of OFDM symbols on which the RACH preamble is configured in the time domain.