Wireless Terminal Random Access Preamble Segmentation
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Solution Overview
Problem
In wireless communication systems, especially those with multiple IoT terminals, preamble collisions during random access lead to increased delay times and inefficient use of radio resources, as multiple terminals often select the same preamble, causing collisions and retransmissions.
Innovation Solution
The system divides preamble detection segments into multiple detection sub-segments, allowing wireless terminals to adjust their preamble transmission timing using previously acquired timing advances (TA), enabling them to transmit preambles in specific sub-segments and reducing collisions by effectively increasing the number of available preamble resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple wireless terminals use the same preamble resources for random access, then connectivity is established, but preamble collisions occur leading to increased delay times and reduced radio resource efficiency
Solution Approach 1:
The preamble detection segment is divided into multiple detection sub-segments, allowing terminals to select different sub-segments for preamble transmission. This segmentation increases the effective number of preamble resources from 64 to 64×N (where N is the number of sub-segments), thereby reducing collision probability while maintaining connectivity establishment reliability
2Reliability
If multiple wireless terminals use the same preamble resources for random access, then connectivity is established, but radio resource usage efficiency decreases due to collisions and retransmissions
Solution Approach 1:
By dividing the detection segment into multiple sub-segments and assigning different preamble resources to each sub-segment, the system increases the total available preamble resources. This reduces the frequency of collisions and retransmissions, thereby improving radio resource usage efficiency while maintaining connectivity establishment
3Ease of operation
If wireless terminals transmit preambles without timing adjustment, then transmission is simple, but collisions increase due to unsynchronized arrivals at the base station
Solution Approach 1:
The base station broadcasts timing advance (TA) information to terminals before random access. Terminals use this pre-acquired TA to adjust their preamble transmission timing, ensuring synchronized arrivals at the base station. This preliminary timing adjustment reduces collisions while maintaining operational simplicity
Solution Approach 2:
The system dynamically adjusts transmission timing based on terminal-specific TA values. Terminals apply timing adjustments according to their distance and channel conditions, allowing flexible timing optimization that reduces collisions while adapting to varying transmission scenarios
Data Source
AI summary
The present disclosure provides an apparatus and a method for random access in a wireless communication system having a base station and wireless terminals, where the wireless terminal can select a detection sub-segment from a preamble detection segment that is divided into a multiple number of detection sub-segments, transmit a random access preamble with the timing adjusted such that the random access preamble is received at the base station in the selected detection sub-segment, and when a random access response message is received from the base station, transmit a terminal identification message to the base station and receive a contention resolution message from the base station.