Uplink Timing Advance Offset Alignment in LTE Systems
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Solution Overview
Problem
In LTE systems, the fixed timing advance offset leads to unaligned symbols in uplink basic and reference units, causing interference and complexity due to different cyclic prefix lengths, which are not resolved by existing methods unless the offset is an integral multiple of 7 symbols.
Innovation Solution
A dynamic timing advance and timing advance offset are used to determine the starting transmission time of uplink basic units relative to downlink basic units, aligning OFDM symbols and reducing interference by configuring the timing advance offset dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a fixed timing advance offset is used to advance the uplink basic unit relative to the downlink basic unit, then the uplink transmission timing is advanced to accommodate propagation delay, but the uplink symbols become misaligned with the uplink reference unit symbols due to different cyclic prefix lengths
Solution Approach 1:
The patent applies dynamics by making the timing advance offset configurable and adjustable rather than fixed. The base station can dynamically set the timing advance offset value through RRC signaling to achieve symbol alignment between uplink basic units and uplink reference units, resolving the contradiction between time advance and alignment precision.
Solution Approach 2:
The patent changes the timing advance offset parameter from a fixed value to a configurable parameter. By adjusting this parameter through RRC signaling, the system can optimize both the time advance requirement and the symbol alignment precision simultaneously, eliminating the misalignment caused by different cyclic prefix lengths.
2Adaptability or versatility
If different fixed timing advance offsets are configured for uplink basic units and uplink reference units, then each unit can be optimized independently, but the symbols remain unaligned causing interference and increased complexity
Solution Approach 1:
The patent merges the timing advance configuration of uplink basic units and uplink reference units by using a unified configurable timing advance offset parameter. This allows the base station to coordinate the timing of both unit types to achieve symbol alignment, eliminating interference while maintaining the ability to independently optimize each unit type through parameter configuration.
Solution Approach 2:
The patent creates a universal timing advance offset parameter that serves both uplink basic units and uplink reference units. This single parameter can be configured through RRC signaling to simultaneously optimize the timing of different unit types, reducing implementation complexity while maintaining adaptability for different scenarios.
Data Source
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AI summary
The present invention provides methods and devices for transmitting and receiving data. The method for transmitting data includes: determining one or more orthogonal frequency division multiplexing (OFDM) symbols for transmitting data in an uplink basic unit, a starting transmission time of the uplink basic unit is preset advance time ahead of a starting transmission time of a downlink basic unit, and the preset advance time is determined according to a dynamic timing advance and a timing advance offset; and transmitting data on the determined one or more OFDM symbols. The problem of unaligned uplink symbols existing in the uplink basic unit and an uplink reference unit when the uplink basic unit and the uplink reference unit have different fixed timing advance offsets in the existing art is solved, thereby decreasing interference among users and the implementation complexity.