Random Access Response PDCCH Scrambling Offset Segmentation
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Solution Overview
Problem
In LTE or LTE-A systems, the existing random access response methods lead to power waste due to missed detection and false alarms, as UEs cannot distinguish between different repetition levels of PDCCHs, resulting in unnecessary retransmissions and resource misallocation.
Innovation Solution
The proposed method involves determining and using level or resource information corresponding to a random access preamble, such as repetition levels or channel quality parameters, to accurately identify and respond to random access preambles, ensuring that random access responses are sent on the correct channels, thereby reducing power waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a same RA-RNTI is used to calculate scrambling code sequences for PDCCHs at different repetition levels, then the calculation process is simplified, but the UE cannot distinguish the PDCCHs at different repetition levels, causing RAR missed detection or false alarm
Solution Approach 1:
The patent segments the RA-RNTI calculation by introducing different offset values for different PRACH repetition levels. Instead of using a single unified RA-RNTI calculation, the system divides the calculation into level-specific segments by adding level-dependent offsets, enabling the UE to distinguish PDCCHs at different repetition levels while maintaining a systematic calculation approach.
Solution Approach 2:
The patent applies local quality by making the RA-RNTI calculation adaptive to local conditions (different PRACH repetition levels). Each repetition level receives a customized RA-RNTI calculation with its specific offset, allowing the system to optimize for each local scenario rather than using a one-size-fits-all approach.
2Ease of operation
If the UE detects PDCCHs at different repetition levels using the same RA-RNTI, then the detection process is simplified, but the UE may mistakenly consider a PDCCH at another repetition level as its own, causing false alarm
Solution Approach 1:
The patent segments the PDCCH detection process by introducing level-specific offsets in the RA-RNTI calculation. This segmentation ensures that PDCCHs at different repetition levels are associated with distinct RA-RNTI values, allowing the UE to correctly identify and distinguish between PDCCHs intended for different repetition levels while maintaining a systematic detection approach.
Solution Approach 2:
The patent introduces the level-specific offset as an intermediary element in the RA-RNTI calculation. This intermediary component acts as a discriminator that enables the UE to correctly identify PDCCHs at different repetition levels, preventing false alarms while maintaining the efficiency of the detection process.
3Productivity
If the base station sends DCI carried by PDCCHs at different repetition levels in one subframe, then the transmission efficiency is improved, but the UE cannot distinguish the PDCCHs, causing power waste due to unnecessary retransmissions
Solution Approach 1:
The patent segments the DCI transmission by associating different repetition levels with distinct RA-RNTI values through level-specific offsets. This segmentation enables the UE to correctly identify and process DCI at different repetition levels within the same subframe, preventing unnecessary retransmissions and reducing power waste while maintaining high transmission efficiency.
Solution Approach 2:
The patent changes the RA-RNTI parameter by introducing level-specific offsets that vary with PRACH repetition levels. This parameter change enables the system to transmit DCI at different repetition levels efficiently while ensuring the UE can distinguish between them, thereby avoiding power waste from failed detections and retransmissions.
4Quantity of substance
If time division multiplexing/frequency division multiplexing is used for random access preambles at different PRACH repetition levels, then the resource allocation is optimized, but a same code resource may be used for different PRACH repetition levels, causing RAR false alarm
Solution Approach 1:
The patent segments the code resource allocation by introducing level-specific offsets in the RA-RNTI calculation. This segmentation ensures that even when the same code resource is reused across different PRACH repetition levels through TDM/FDM, each repetition level is associated with a unique RA-RNTI value, preventing RAR false alarms while optimizing code resource utilization.
Solution Approach 2:
The patent applies local quality by making the RA-RNTI calculation adaptive to local conditions (different PRACH repetition levels). Each repetition level receives a customized RA-RNTI calculation with its specific offset, allowing the system to reuse code resources efficiently through TDM/FDM while ensuring reliable RAR detection through level-specific identification.
Data Source
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Figure 3
Figure 4A
AI summary
A random access response method, a base station, and a terminal are provided and can reduce power waste of the terminal. The method includes: receiving a random access preamble sent in an enhanced manner; determining at least one of level information or resource information corresponding to the random access preamble sent in the enhanced manner; and sending a random access response RAR of the random access preamble according to the at least one of the level information or the resource information, where the RAR is carried by a physical downlink shared channel PDSCH.