Downlink Control Information Segmentation for Millimeter Wave Reliability
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Solution Overview
Problem
Current wireless communication systems, particularly in 5G, face challenges in ensuring the reliability of downlink control information (DCI) transmission due to high latency and variability in channel conditions, especially in millimeter wave frequencies where signal attenuation is rapid, leading to reduced coverage and increased costs with digital beamforming.
Innovation Solution
The method involves segmenting downlink control information into multiple candidates, aggregating them across control resource blocks, and using cyclic redundancy check (CRC) and additional scrambling sequences to enhance reliability, allowing for efficient transmission and decoding, even in high-frequency bands, by reducing code rates and optimizing resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If downlink control information is transmitted using conventional methods in millimeter wave frequencies, then transmission speed can be maintained, but reliability deteriorates due to rapid signal attenuation and high latency
Solution Approach 1:
The downlink control information is divided into multiple segments, with each segment transmitted through separate control resource sets. This segmentation allows the information to be transmitted through multiple paths, reducing the impact of signal attenuation in any single path and improving overall transmission reliability in millimeter wave frequencies
Solution Approach 2:
Cyclic redundancy check (CRC) sequences are attached to the downlink control information before transmission, and scrambling sequences are applied in advance. These preliminary error detection and protection mechanisms enable the receiver to identify and correct transmission errors, compensating for the harmful effects of millimeter wave signal attenuation
2Reliability
If digital beamforming is used to improve coverage in millimeter wave frequencies, then signal reliability can be enhanced, but cost increases due to rapid signal attenuation requirements
Solution Approach 1:
The control information transmission is segmented across multiple control resource sets, allowing the system to achieve diversity gain without requiring complex digital beamforming. This segmentation approach provides coverage enhancement through spatial and temporal diversity while avoiding the high complexity and cost of full digital beamforming implementation
Solution Approach 2:
Scrambling sequences and CRC sequences serve as intermediaries that protect the downlink control information from the harmful effects of channel conditions. These sequences enable error detection and protection without requiring complex beamforming operations, reducing device complexity while maintaining coverage reliability
3Productivity
If downlink control information is transmitted without segmentation, then transmission simplicity is maintained, but latency increases due to retransmission requirements
Solution Approach 1:
By segmenting the downlink control information into multiple parts transmitted through different control resource sets, the system enables parallel transmission paths. This segmentation reduces the probability of complete transmission failure and the need for retransmissions, thereby reducing latency while maintaining transmission simplicity through the use of standard CRC and scrambling mechanisms
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3(a)~3(b)
AI summary
The present invention provides a method by which a terminal receives downlink control information (DCI) in a wireless communication system. Particularly, the method can acquire the DCI by detecting a plurality of first DCI candidates in a plurality of control resource block (RB) sets, descrambling a cyclic redundancy check (CRC) included in each of the plurality of first DCI candidates, and aggregating second DCI candidates, from among the plurality of first DCI candidates, descrambled on the basis of the same scrambling sequence.