Uplink Transmission Diversity via Cyclic Precoding
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Solution Overview
Problem
In 5G NR systems, UE with partial-coherent or non-coherent transmission capabilities face reduced performance and coverage due to inadequate power allocation during single-rank transmissions, especially at the cell edge, where channel conditions are poor and phase or power differences between antennas are not adequately reflected in the precoding matrix.
Innovation Solution
Introducing delay processing and cyclic precoding on multiple antenna ports using candidate codewords to introduce transmission diversity gain, allowing full-power utilization and adjusting precoding in the frequency domain to match actual antenna conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If codebook-based precoding is used for uplink transmission, then transmission structure is simplified and device complexity is reduced, but transmission performance deteriorates when channel conditions change rapidly or antenna phase/power differences are significant
Solution Approach 1:
The patent applies dynamics by making the precoding matrix adjustable and adaptive rather than fixed. The base station can dynamically select from multiple candidate precoding matrices based on current channel conditions, allowing the system to adapt to rapidly changing channels and antenna characteristics while maintaining relatively simple device structure.
Solution Approach 2:
The patent changes the precoding parameters by introducing multiple candidate precoding matrices with different configurations. The base station selects the most appropriate precoding matrix from these candidates based on channel state information, enabling parameter optimization without increasing terminal device complexity.
2Ease of operation
If fixed codebook precoding is applied, then implementation is simple and ease of operation is improved, but transmission diversity gain is insufficient and coverage is reduced
Solution Approach 1:
The patent makes the precoding system multi-functional by supporting both fixed codebook operation and dynamic candidate matrix selection. The base station can choose between different precoding approaches based on channel conditions, providing both the simplicity of fixed codebooks when appropriate and the diversity gain of adaptive selection when needed.
Solution Approach 2:
The system transitions from static fixed codebook precoding to dynamic candidate matrix selection based on channel conditions. This allows the system to maintain simplicity when channels are stable while gaining diversity benefits when channels vary rapidly or exhibit significant antenna differences.
3Productivity
If TPMI indicates antennas incapable of coherent transmission for same data layer, then resource allocation is efficient, but optimal uplink transmission precoding cannot be achieved and performance deteriorates
Solution Approach 1:
The patent implements feedback mechanisms where the base station receives channel state information from the terminal and uses this feedback to select appropriate precoding matrices from candidate sets. This ensures that antennas incapable of coherent transmission are not assigned to the same data layer, maintaining both resource efficiency and transmission performance.
Solution Approach 2:
The base station pre-configures multiple candidate precoding matrices that are designed to avoid assigning incompatible antennas to the same layer. By preparing these matrices in advance based on anticipated channel conditions and antenna capabilities, the system ensures optimal performance without requiring complex real-time adjustments.
Data Source
AI summary
Embodiments of the present disclosure disclose an uplink transmission method, an uplink transmission scheduling method and a device. The uplink transmission method is applied to a terminal and includes: performing delay processing of an uplink signal on multiple antenna ports and then transmitting the uplink signal.