Downlink DCI Parsing Across Mixed RNTI-Scrambled Data Channels
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Solution Overview
Problem
In a 5G mobile communication system, when downlink control information (DCI) scrambled by a first RNTI schedules a downlink data channel scrambled by a second RNTI different from the first, the terminal device cannot align the functions of the downlink assignment index (DAI) and/or frequency domain resource assignment (FDRA) domains, leading to misinterpretation of information.
Innovation Solution
The method involves receiving DCI with a first RNTI and a downlink data channel scrambled by a second RNTI, aligning the DAI and/or FDRA domains by using a dedicated bandwidth part (BWP) configured for the terminal device, ensuring correct data transmission by parsing the frequency domain resources based on bit sequences adjusted to match the BWP or padded bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If DCI is scrambled with a first RNTI and schedules a downlink data channel scrambled with a second RNTI, then scheduling flexibility and resource allocation efficiency are improved, but the terminal device cannot determine whether the DAI domain and/or FDRA domain corresponds to the first RNTI or the second RNTI, leading to misalignment in understanding
Solution Approach 1:
The patent introduces a third RNTI (first group RNTI) as an intermediary that scrambles the DCI, creating a clear association between the control information and the corresponding data channel. This mediator resolves the ambiguity by establishing a consistent identification mechanism that links the DAI domain and FDRA domain to the correct RNTI, preventing information loss while maintaining scheduling flexibility.
Solution Approach 2:
The patent changes the scrambling parameter (RNTI) used for DCI from the traditional first RNTI to a first group RNTI, which is specifically associated with the downlink data channel scrambled by the second RNTI. This parameter change clarifies the functional association between DCI fields and RNTIs, ensuring that the terminal device can correctly determine which RNTI corresponds to which domain without ambiguity.
2Ease of manufacture
If the terminal device uses traditional DCI parsing methods, then protocol compatibility is maintained, but incorrect data transmission occurs due to misalignment in DAI and FDRA domain interpretation
Solution Approach 1:
The patent implements a feedback mechanism where the terminal device uses the first group RNTI to identify and interpret the DAI domain and FDRA domain in the DCI. This feedback loop ensures that the terminal device correctly determines the association between control information and data channel, preventing misalignment and ensuring reliable data transmission while maintaining protocol compatibility through standardized parsing procedures.
3Adaptability or versatility
If the terminal device receives DCI scrambled with a first RNTI for unicast and data channel scrambled with a second RNTI for multicast, then service differentiation is improved, but the terminal device cannot correctly interpret the DAI domain and FDRA domain functions
Solution Approach 1:
The patent applies local quality by assigning specific RNTI types to specific service types: the first RNTI is used for unicast service differentiation, while the first group RNTI is used for multicast service identification. This localized assignment ensures that the DAI domain and FDRA domain are correctly interpreted according to the service type, maintaining service differentiation while preventing information loss through clear functional association.
Data Source
AI summary
A data transmission (including receiving and sending) method is disclosed. According to the data transmission method, a terminal device receives downlink control information (DCI), where cyclic redundancy check (CRC) of the DCI is scrambled by using a first RNTI, the DCI is used to schedule a first downlink data channel, and the first downlink data channel is scrambled by using a second RNTI; and the terminal device receives the first downlink data channel based on the DCI. The DCI includes a DAI domain and/or an FDRA domain. The DAI domain indicates a count of first HARQ-ACK information in a first HARQ-ACK codebook, and the first HARQ-ACK codebook corresponds to the first RNTI. The FDRA domain indicates, within a frequency domain range of a public frequency resource, a scheduled frequency domain resource on the first downlink data channel.