Beam-Specific Timing Advance Estimation in Millimeter Wave Uplink
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Solution Overview
Problem
In wireless communication systems, especially with hybrid beamforming in the millimeter wave band, the change in channel characteristics across individual beams leads to timing misalignment issues, which existing methods fail to address effectively.
Innovation Solution
A method for estimating and applying a Timing Advance (TA) value for each beam based on its unique channel characteristics during the beam scanning process, using preambles transmitted by User Equipment (UE) to the Base Station (BS), allowing for optimized timing alignment in uplink transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If hybrid beamforming is used in massive MIMO to reduce hardware complexity and improve flexibility, then device complexity and resource allocation flexibility are improved, but timing misalignment occurs between beams due to different channel characteristics
Solution Approach 1:
The patent segments the timing alignment process by beam, where each beam's timing advance value is independently estimated and applied. The base station receives random access preambles on different beams, estimates timing advance values separately for each beam, and applies beam-specific timing adjustments. This segmentation resolves the timing misalignment issue caused by hybrid beamforming while maintaining the hardware complexity benefits of the beamforming architecture.
Solution Approach 2:
The patent implements local quality by applying different timing advance values to different beams based on their specific channel characteristics. Instead of using a uniform timing alignment approach, the system tailors the timing adjustment to each beam's propagation conditions, thereby achieving accurate timing alignment for each directional beam while preserving the overall system flexibility.
2Ease of operation
If a single timing advance value is used for all beams in massive MIMO, then device complexity is reduced, but timing misalignment occurs due to varying channel characteristics across beams
Solution Approach 1:
The patent divides the timing alignment operation into beam-specific segments, where each beam receives its own timing advance value. The base station processes random access preambles on different beams independently, estimates separate timing advance values for each beam, and applies corresponding timing adjustments. This segmentation maintains operational simplicity while achieving accurate uplink synchronization for each beam.
Solution Approach 2:
The patent changes the timing advance parameter from a single uniform value to multiple beam-specific values. By adjusting the timing advance parameter individually for each beam based on measured channel characteristics, the system achieves accurate uplink synchronization without significantly complicating the operational procedure.
3Measurement precision
If beam-specific timing advance values are estimated for each beam in hybrid beamforming, then timing alignment accuracy is improved, but the processing complexity and overhead increase
Solution Approach 1:
The patent performs preliminary timing advance estimation during the random access procedure, which occurs before normal data transmission. By estimating beam-specific timing advance values during the initial access phase using random access preambles, the system prepares the timing alignment parameters in advance, thereby achieving high timing precision without adding complexity to the ongoing data transmission processing.
Solution Approach 2:
The system uses the random access preambles transmitted by user equipment for dual purposes: both for establishing initial access and for estimating beam-specific timing advance values. This self-service approach allows the system to obtain timing synchronization information without requiring additional dedicated signaling or measurement resources, thereby reducing processing overhead while maintaining high timing precision.
Data Source
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AI summary
Provided is a method for estimating a timing advance (TA) for each beam in a wireless communication system. First, a terminal transmits K preambles, to which K mutually different beam formings are applied, to a base station. The base station estimates the TA for each of the K received preambles. The base station can determine the final TA value of the terminal on the basis of the TAs estimated for each of the K preambles.