Uplink Precoding Codebook Segmentation for 5G NR Coverage
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing uplink transmission due to limitations in precoding matrix indicators, particularly in 5G/NR systems operating in higher frequency bands, which affect radio wave propagation and transmission distance.
Innovation Solution
The implementation of a codebook for precoding matrices constructed based on the matrix Wn=I-2ununH, where I is an identity matrix and un is a n×1 vector, to enhance uplink transmission by providing precise precoding for antenna ports, improving beamforming and coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional precoding matrix indicators are used in 5G/NR systems operating in higher frequency bands, then device complexity is reduced and ease of operation is maintained, but uplink transmission coverage and efficiency deteriorate due to limitations in radio wave propagation
Solution Approach 1:
The codebook is segmented into multiple subsets, each optimized for specific transmission scenarios and frequency bands. This segmentation allows the system to select appropriate precoding matrices tailored to specific propagation conditions, thereby improving uplink coverage without requiring the UE to process the entire large codebook, thus managing complexity effectively
Solution Approach 2:
The patent introduces new parameters including the codebook subset index (CSI-CS) and modified precoding matrix indicators that enable dynamic selection from segmented codebook subsets. These parameter changes allow adaptive optimization of precoding for higher frequency bands, improving transmission reliability while maintaining manageable signal overhead through efficient parameter encoding
2Productivity
If a comprehensive codebook with all possible precoding matrices is implemented, then uplink transmission efficiency is improved through optimal precoding selection, but signaling overhead and message length increase
Solution Approach 1:
The patent extracts and reports only the necessary codebook subset information through the CSI-CS parameter, rather than transmitting complete precoding matrix details. This extraction approach enables the network to identify the appropriate codebook subset with minimal signaling overhead, while still achieving optimal precoding selection for improved uplink transmission efficiency
Solution Approach 2:
The codebook is pre-organized into subsets with specific characteristics suitable for different transmission conditions. This preliminary organization allows the UE and network to efficiently reference and select appropriate precoding matrices without extensive signaling, as the structured subsets enable rapid identification and selection based on current channel conditions
Data Source
AI summary
Apparatuses and methods for uplink (UL) transmission. A method performed by a user equipment (UE) includes receiving a transmit precoding matrix indicator (TPMI) for a transmission of a physical uplink shared channel (PUSCH) and transmitting the PUSCH based on the TPMI. The TPMI indicates a precoding matrix from a codebook for P antenna ports. The codebook includes precoding matrices constructed based on at least one column of a matrixWn=I-2ununH,where l is an identity matrix, un is a n×1 vector, n≤P, andunHis a Hermitian transpose of the vector un.