Dynamic TTI Random Access for Wireless Uplink Scheduling
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Solution Overview
Problem
In LTE and LTE-A systems, reducing the Transmission Time Interval (TTI) for random access in wireless communications leads to access failures due to channel environment limitations and scheduling status, resulting in prolonged random access times.
Innovation Solution
A method where a base station sends Downlink Control Information (DCI) carrying transmission time unit indication information, allowing user equipment to correctly receive and respond to random access responses even with shorter TTIs, by indicating the time length of transmission units and transport block locations, enabling accurate message identification and transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the Transmission Time Interval (TTI) is reduced to shorten random access time, then the random access time is reduced, but the UE cannot correctly receive messages due to channel environment limitations and scheduling status
Solution Approach 1:
The patent applies dynamics by making the TTI length configurable and adaptable. The base station can dynamically select between a first TTI length (shorter) and a second TTI length (longer) based on channel conditions and scheduling status. This allows the system to transition from a static TTI structure to a dynamic one that can optimize between speed and reliability in different scenarios
Solution Approach 2:
The patent changes the TTI length parameter from a fixed value to a variable that can take different values (first TTI length or second TTI length). By modifying this critical parameter based on system conditions, the patent enables the random access procedure to adapt its timing characteristics, allowing shorter TTIs when conditions permit to reduce access time, and longer TTIs when reliability is concerns
2Productivity
If the TTI is directly reduced without considering channel environment and scheduling status, then the transmission time is reduced, but the UE cannot correctly receive the message resulting in access failure
Solution Approach 1:
The patent implements feedback mechanisms where the base station monitors channel environment and scheduling status, then uses this feedback information to determine the appropriate TTI length for random access messages. This closed-loop approach ensures that TTI reduction decisions are based on actual system conditions rather than fixed configurations, preventing access failures caused by inappropriate TTI selection
Solution Approach 2:
The system transitions from static TTI configuration to dynamic TTI selection based on real-time conditions. The base station can adaptively choose between different TTI lengths during the random access procedure, allowing the system to optimize for both speed and reliability depending on current channel and scheduling conditions
Data Source
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AI summary
The present invention relates to the field of wireless communications technologies, and discloses a random access method and apparatus, a base station, and UE, to resolve a problem of long time required by random access. According to embodiments of the present invention, a base station receives a random access preamble sent by user equipment UE, where the random access preamble is used to indicate that the UE has a first transmission capability; the base station sends DCI to the UE by using a PDCCH; the base station sends an RAR for the random access preamble to the UE by using a DL-SCH transport block indicated by the DCI; and the base station receives a UL-SCH transport block sent by the UE according to uplink scheduling information carried by the RAR. Solutions provided by the embodiments of the present invention are applicable to a process in which UE accesses a network.