PRACH Resource Segmentation for MTC UE Random Access
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Solution Overview
Problem
Current methods for Machine Type Communication (MTC) User Equipment (UE) in LTE/LTE-A systems face challenges in meeting access requirements due to high costs and performance degradation, particularly in scenarios with penetration loss, where conventional LTE UE coverage is compromised, necessitating enhanced uplink and downlink coverage for MTC UE.
Innovation Solution
A method and device for sending and receiving a random access sequence, involving the determination of preset random access resources for the Physical Random Access Channel (PRACH), where random access sequences are sent on these resources, and a random access response is detected within a specified time interval, with mechanisms for retransmission based on resource availability and timing configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If MTC UE adopts low-cost configuration (reduction of receiving antennae, base-band processing bandwidth), then cost is reduced, but coverage performance deteriorates
Solution Approach 1:
The patent changes the parameter of random access sequence length from conventional values to extended lengths (e.g., 8320 subcarriers instead of 1200), thereby improving uplink coverage for low-cost MTC UE without requiring additional hardware components
Solution Approach 2:
The patent divides the PRACH resource into multiple resource segments (e.g., 4 segments of 2048 subcarriers each) that can be transmitted sequentially, allowing low-cost UEs with limited base-band processing bandwidth to process each segment separately while achieving extended coverage
2Reliability
If random access sequence length is extended to improve coverage, then coverage performance is improved, but base-band processing bandwidth requirement increases
Solution Approach 1:
The extended random access sequence is divided into multiple resource segments that are transmitted in different time slots. Low-cost MTC UE can process each segment separately with reduced base-band processing bandwidth requirements, while still achieving extended coverage through cumulative transmission
Solution Approach 2:
The patent uses periodic transmission of random access sequence segments across multiple subframes, allowing low-cost UEs to process each period with limited bandwidth while achieving extended coverage through repeated transmissions over time
3Reliability
If MTC UE is located in severe scenarios (basement, wall corner), then penetration loss increases, but access quality requirement remains the same
Solution Approach 1:
The patent extends the random access sequence length and adjusts PRACH resource parameters to increase transmission energy, thereby compensating for penetration loss in severe scenarios such as basements and wall corners while maintaining access quality
Solution Approach 2:
The system pre-configures multiple PRACH resources and resource segments that can be used for retransmission, allowing MTC UE in severe scenarios to attempt access multiple times with different resources until successful connection is established
Data Source
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AI summary
A method and device for sending and receiving a random access sequence. wherein the method for sending a random access sequence includes: determining one or more preset random access resources forming a Physical Random Access Channel (PRACH); and sending a first random access sequence on the one or more preset random access resources. By the present invention, the problem that an access requirement cannot be met by a random access sequence processing method in a related art is solved, and the effect of improving random access efficiency and accuracy is further achieved.