Dynamic Guard Period Allocation in LTE TDD Systems
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Solution Overview
Problem
In LTE TDD wireless communication systems, the fixed guard period resources are not efficiently utilized due to a constant time length, leading to wasted resources and reduced system performance, especially for user equipment (UE) with varying round-trip times, resulting in inefficient handover between downlink and uplink signals.
Innovation Solution
The method involves determining a guard period level for each UE based on its round-trip time, allowing the UE to adjust the guard period length within the fixed guard period resources, enabling the use of these resources for uplink data transmission, thereby optimizing resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed guard period length is used for all UEs, then handover between downlink and uplink signals can be ensured for UEs at the cell edge, but system resources are wasted and transmission efficiency decreases for UEs closer to the base station
Solution Approach 1:
The patent segments the guard period resources by introducing multiple guard period levels (first guard period level and second guard period level) instead of using a single fixed guard period for all UEs. This segmentation allows different UEs to use appropriately sized guard periods based on their round-trip times, ensuring reliable handover for cell edge UEs while improving transmission efficiency for closer UEs.
Solution Approach 2:
The patent makes the guard period length dynamic by configuring different guard period levels according to UE-specific round-trip times. The base station determines which guard period level to allocate to each UE based on measured round-trip time, allowing the guard period to adapt dynamically to different propagation conditions rather than being fixed for all UEs.
2Reliability
If a larger guard period is configured to accommodate UEs at the cell edge, then handover reliability improves, but resource utilization deteriorates for the entire cell
Solution Approach 1:
The patent applies local quality by allocating different guard period lengths to different UEs based on their specific needs. UEs at the cell edge receive larger guard periods (first guard period level) to ensure reliable handover, while UEs closer to the base station receive smaller guard periods (second guard period level). This localized optimization ensures that each UE receives the minimum necessary guard period for reliable operation without unnecessarily consuming system resources.
Solution Approach 2:
The patent changes the guard period parameter from a fixed value to a configurable parameter with multiple levels. The base station measures the round-trip time for each UE and configures the appropriate guard period level accordingly, transforming the guard period from a static system-wide parameter to a dynamic UE-specific parameter that optimizes both reliability and resource utilization.
3Stability of the object's composition
If UEs wait for the fixed guard period duration before transmitting uplink data, then handover timing is synchronized, but waiting time increases for UEs with smaller round-trip times
Solution Approach 1:
The patent introduces dynamics to the guard period duration by configuring different guard period levels based on UE round-trip times. Instead of all UEs waiting for the same fixed duration, each UE waits for a guard period length appropriate to its propagation delay. This dynamic adjustment maintains timing synchronization for handover while minimizing unnecessary waiting time for UEs with smaller round-trip times.
Solution Approach 2:
The patent changes the guard period parameter from a fixed system-wide value to a configurable UE-specific value. By measuring round-trip time and configuring appropriate guard period levels, the system adjusts the waiting time parameter to match actual propagation conditions, maintaining synchronization stability while reducing time loss for UEs that would otherwise wait unnecessarily long.
Data Source
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AI summary
Embodiments of the present invention provide a method and a device for transmitting data relate to the technical field of communications and can effectively improve resource utilization of the system. The method for transmitting data includes: a user equipment receives downlink data sent from a base station through downlink resources of a special subframe; the user equipment determines its corresponding guard period level, the guard period level corresponds to a round-trip time of the user equipment and indicates a length of an orthogonal frequency division multiplexing (OFDM) symbol in a guard period corresponding to the user equipment in the special subframe; the user equipment determines, according to its corresponding guard period level, a position of uplink resources corresponding to the user equipment in guard period resources of the special subframe; and the user equipment sends uplink data to the base station through the uplink resources corresponding to the user equipment in the guard period resources of the special subframe. Embodiments of the present invention can be applied in a wireless communication system.