Terminal Scrambling Sequence Initialization for Downlink Control
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Solution Overview
Problem
Current communication systems, particularly in LTE and NR, face inefficiencies in the transmission and reception of downlink data due to complexities in scrambling sequences for physical downlink control channels, which affect the terminal apparatus and base station apparatus's ability to manage multiple serving cells effectively.
Innovation Solution
The proposed solution involves a terminal apparatus and base station apparatus that utilize a scrambling sequence initialized based on NID and NRNTI, where NID is determined by a higher layer parameter Control-scrambling-Identity or physical layer cell identity, depending on configuration, to efficiently transmit and receive data on physical downlink control channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a scrambling sequence is used for physical downlink control channel transmission, then reliability of downlink control information is improved, but device complexity increases due to multiple parameters (NID, NRNTI, Control-scrambling-Identity) needed for initialization
Solution Approach 1:
The patent applies local quality by making the NID parameter configurable at different levels: a cell-specific NID can be used for common control channels, while UE-specific NID can be used for dedicated channels. This allows each part of the system to use the appropriate level of complexity based on its specific requirements, improving reliability where needed while managing overall device complexity.
Solution Approach 2:
The patent introduces dynamic selection of NID values based on higher layer parameters and physical layer cell identity. The system can dynamically switch between different NID configurations depending on the operational mode, serving cell configuration, and whether Control-scrambling-Identity is configured, thereby adapting the complexity level to current system conditions.
2Reliability
If multiple parameters are used for scrambling sequence initialization, then security and reliability are improved, but ease of operation deteriorates due to complex parameter management
Solution Approach 1:
The patent implements preliminary action by pre-configuring the Control-scrambling-Identity parameter through higher layer signaling before actual downlink control information transmission. This allows the terminal apparatus to have the necessary parameters ready in advance, simplifying the operation during actual transmission while maintaining security and reliability through proper parameter initialization.
Solution Approach 2:
The system employs self-service mechanisms where the terminal apparatus automatically determines the appropriate NID value based on whether Control-scrambling-Identity is configured and the current serving cell context. This automated parameter selection reduces manual configuration complexity while ensuring reliable scrambling sequence generation.
3Adaptability or versatility
If NID is determined based on higher layer parameter Control-scrambling-Identity, then adaptability is improved, but manufacturing precision requirements increase for parameter configuration
Solution Approach 1:
The patent achieves universality by designing the NID determination mechanism to work across multiple scenarios: it can use Control-scrambling-Identity when configured, fall back to physical layer cell identity when not configured, and adapt to different serving cell configurations. This multi-functional approach improves adaptability while the standardized fallback mechanisms ensure consistent parameter configuration across different implementation scenarios.
Data Source
AI summary
Efficient downlink transmission is implemented. A terminal apparatus includes: a receiver configured to receive a sequence of bits in a physical downlink control channel, wherein the sequence of bits is scrambled with a scrambling sequence initialized by cinit, the cinit is given based at least on NID and NRNTI, the NID is given based at least on a higher layer parameter Control-scrambling-Identity in a case that the higher layer parameter Control-scrambling-Identity is configured and the NRNTI is given based at least on a Cell-Radio Network Temporary Identifier (C-RNTI), and the NID is given based at least on a physical layer cell identity in a case that the higher layer parameter Control-scrambling-Identity is configured and the NRNTI is not given based on the C-RNTI.