Uplink Timing Advance Alignment Across Multiple NR Subcarrier Spacings
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Solution Overview
Problem
In the new radio (NR) system, the different subcarrier spacings (SCSs) lead to different uplink synchronization granularities, causing inaccuracies in timing advance commands, which can result in increased intra-cell interference due to misalignment of uplink transmissions.
Innovation Solution
The method involves correlating timing advance commands with a reference SCS used by the terminal equipment to ensure accurate uplink transmission timing by aligning the understanding of the reference SCS between the network device and the terminal equipment, using predefined or designated SCS values and control signaling to update BWP configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If timing advance commands are transmitted without correlating with reference SCS, then the device complexity is reduced, but the measurement precision of uplink transmission timing deteriorates
Solution Approach 1:
The patent introduces reference SCS as an intermediary parameter that mediates between the timing advance command and the uplink transmission timing. The network device indicates the reference SCS through which the terminal equipment calculates the timing advance, ensuring both sides use the same reference for accurate timing alignment without requiring complex direct signaling of timing values.
Solution Approach 2:
The patent changes the parameter representation by using reference SCS values (15, 30, 60, 120 kHz) as the basis for timing advance calculation. Instead of directly signaling timing advance values, the system signals the reference SCS parameter, and the terminal equipment derives the timing advance based on this parameter and its corresponding synchronization granularity, simplifying the signaling while maintaining precision.
2Adaptability or versatility
If different SCSs are supported without SCS-specific timing advance commands, then the adaptability of the system is improved, but the manufacturing precision of timing alignment deteriorates
Solution Approach 1:
The patent segments the timing advance calculation by creating separate timing advance groups (TAGs) for different reference SCS values. Each TAG is associated with a specific reference SCS (15, 30, 60, or 120 kHz), allowing the system to support multiple SCS configurations while maintaining precise timing alignment within each group by using SCS-appropriate synchronization granularities.
Solution Approach 2:
The patent makes the timing advance calculation dynamic by allowing the terminal equipment to select the appropriate synchronization granularity based on the indicated reference SCS. When the network device changes the reference SCS indication, the terminal equipment dynamically adjusts its timing advance calculation using the corresponding granularity from the set {16×64×2^-μ×Tc}, enabling flexible adaptation to different SCS configurations while maintaining precision.
Data Source
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AI summary
A method and apparatus for acquiring uplink transmission timing advance and a communication system. The method includes: a network device obtains a timing advance command value (TA), the TA being related to a first reference subcarrier bandwidth (SCS) used by a terminal equipment for calculating timing advance (TTA); and the network device transmits a timing advance command (TA command), the TA command including the TA. Hence, the terminal equipment may be assisted in obtaining accurate timing advance of uplink transmission.