Multi-Dimensional PRACH Structure for Accurate RTD Estimation
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Solution Overview
Problem
The existing PRACH structure in 5G communication systems is inadequate for accurately estimating round trip delays in terahertz band communication, leading to inaccurate timing advance calculations and potential failure in random access procedures due to symbol length reduction.
Innovation Solution
A new PRACH structure is introduced with multiple dimensions, incorporating primary and secondary signal parts to measure delays within a symbol and in units of symbols, allowing accurate determination of round trip delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the PRACH structure uses a single symbol section for delay measurement, then the device complexity is low, but the measurement precision is insufficient for terahertz band communication
Solution Approach 1:
The PRACH structure is segmented into multiple dimensions: primary signal parts for measuring delays within a symbol (fine delay) and secondary signal parts for measuring delays in units of symbols (coarse delay). This segmentation allows accurate round trip delay estimation without requiring a single excessively complex measurement mechanism.
Solution Approach 2:
The patent introduces a multi-dimensional PRACH structure that extends beyond the traditional single-symbol measurement approach. By adding temporal dimensions (multiple signal parts across different time positions) and hierarchical measurement levels (within-symbol and between-symbol delays), the system achieves higher measurement precision in terahertz band communication.
2Productivity
If the symbol length is reduced for high data transmission rates, then the productivity increases, but the reliability decreases due to inadequate delay coverage
Solution Approach 1:
The delay measurement is segmented into two hierarchical levels: fine delay measurement within the symbol (using primary signal parts) and coarse delay measurement between symbols (using secondary signal parts). This allows the system to maintain reliability even with reduced symbol lengths by distributing the measurement function across multiple segments.
Solution Approach 2:
The patent performs preliminary delay estimation using the multi-dimensional PRACH structure before actual data transmission. By measuring both within-symbol and between-symbol delays in advance, the system can compensate for timing variations and ensure reliable random access procedures even with shorter symbols required for high data rates.
Data Source
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AI summary
The disclosure relates to a 5th generation (5G) or 6th generation (6G) communication system for supporting a data transmission rate higher than a 4th generation (4G) communication system such as long term evolution (LTE). A user equipment (UE) is provided. The UE includes a transceiver, and a controller configured to receive system information including information related to transmission of a random access preamble, and to transmit a physical random access channel (PRACH) including the random access preamble. The PRACH includes at least one primary signal part including a first sequence for measuring a first delay within a symbol, and at least one secondary signal part including a second sequence for measuring a second delay in units of symbols, and a round trip delay (RTD) between the UE and the base station may be determined based on the first delay within the symbol and the second delay in units of symbols.