PDCCH Scrambling Sequence Initialization by Aggregation Level
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Solution Overview
Problem
Current communication systems, such as LTE and NR, face inefficiencies in determining the size of information and number of modulation symbols/coded symbols/resource elements, which affects the reception and transmission of downlink control information.
Innovation Solution
The proposed solution involves a terminal apparatus and base station apparatus that scramble the sequence of coded bits for downlink control information using a scrambling sequence initialized based on the aggregation level of the PDCCH, enabling efficient decoding and transmission of downlink control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the scrambling sequence is initialized without considering aggregation level, then the initialization process is simple, but the downlink transmission efficiency is reduced
Solution Approach 1:
The patent changes the initialization parameters of the scrambling sequence by incorporating the aggregation level (AL) as an additional parameter. Specifically, the initialization formula is modified to include AL, transforming the sequence from c(i) to c(i, AL), where different aggregation levels generate different scrambling sequences. This parameter change enables more efficient downlink transmission by allowing the terminal to differentiate and efficiently process PDCCH messages with different aggregation levels, thereby resolving the contradiction between transmission efficiency and initialization complexity.
2Productivity
If the scrambling sequence is initialized based on aggregation level, then the downlink transmission efficiency is improved, but the initialization complexity increases
Solution Approach 1:
The patent modifies the scrambling sequence initialization by adding the aggregation level as a parameter. The initialization formula becomes c(i) = (c_init × 2^μ + n_RNTI) mod 2, where c_init includes aggregation level information. This parameter enhancement improves transmission efficiency by enabling better differentiation of control messages while maintaining a structured initialization process that manages complexity through systematic parameter incorporation.
Solution Approach 2:
The patent applies preliminary action by pre-defining the relationship between aggregation level and scrambling sequence initialization. The system预先 establishes that different aggregation levels correspond to specific initialization values, allowing the terminal to quickly determine the appropriate scrambling sequence without complex real-time calculations. This preliminary configuration resolves the contradiction by preparing the system in advance, reducing runtime complexity while maintaining high transmission efficiency.
Data Source
AI summary
A terminal apparatus includes: a monitor unit configured to monitor a first PDCCH candidate with aggregation level 8 and a second PDCCH candidate with aggregation level 16 in a CORESET mapped to one OFDM symbol; and a receiver configured to receive a PDSCH, by assuming that a symbol of the PDSCH is mapped to a resource element that is not overlapping the second PDCCH candidate, based on a PDCCH detected in the first PDCCH candidate, the PDCCH scheduling the PDSCH, wherein a CCE that constitutes the first PDCCH candidate and has a lowest index is identical to a CCE that constitutes the second PDCCH candidate and has a lowest index, and a plurality of the CCEs constituting the CORESET each include six contiguous REGs in a frequency domain.