Reference Signal Multiplexing for Wireless Systems
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Solution Overview
Problem
Existing radio communications systems face limitations in the number of reference signal sequences that can be secured due to the restrictions imposed by multiplexing methods like distributed FDM, particularly when multiple reference signals with different transmission bandwidths are involved.
Innovation Solution
A novel resource allocation method that allows for frequency- and time-multiplexing of reference signals based on their usage purposes, allocating separate resources for demodulation/detection reference signals and independent CQI estimation reference signals, thereby reducing the number of reference signals multiplexed at the same timing and increasing the number of sequences that can be secured.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If distributed FDM multiplexing is used to transmit multiple reference signals with different transmission bandwidths, then the system can support diverse reference signal requirements, but the number of reference signal sequences that can be secured decreases
Solution Approach 1:
The patent segments reference signals into two categories: demodulation/detection reference signals and independent reference signals. This segmentation allows different multiplexing strategies to be applied to each category, thereby securing more sequences overall. Specifically, demodulation reference signals are allocated dedicated resources while independent reference signals share resources through distributed FDM, resolving the contradiction between supporting diverse bandwidths and securing sufficient sequences.
Solution Approach 2:
The patent introduces a new dimension of resource allocation by separating reference signal handling into two distinct resource allocation paths. Instead of treating all reference signals uniformly in the frequency domain, the system creates a hierarchical structure where demodulation reference signals receive priority allocation and independent reference signals utilize remaining resources, effectively adding a temporal/resource priority dimension to the allocation process.
2Productivity
If multiple reference signals are multiplexed at the same timing using distributed FDM, then frequency resource utilization is improved, but the number of available reference signal sequences is reduced
Solution Approach 1:
The patent extracts demodulation/detection reference signals from the distributed FDM multiplexing pool and allocates them separate dedicated resources. This extraction reduces the number of reference signals that must share the same frequency resources through distributed FDM, thereby increasing the number of available sequences while maintaining efficient frequency resource utilization for the remaining independent reference signals.
3Productivity
If the same reference signal resource is shared among multiple users, then resource efficiency is improved, but measurement precision for channel estimation and CQI deteriorates
Solution Approach 1:
The patent applies local quality by providing high-quality dedicated reference signal resources to demodulation/detection reference signals that require high measurement precision for accurate channel estimation and CQI measurement. Meanwhile, independent reference signals that have less stringent precision requirements utilize shared distributed FDM resources, optimizing overall system efficiency while maintaining necessary measurement accuracy for critical functions.
Data Source
AI summary
A reference signal of a user equipment to which a resource (LB#1) is allocated for a L1/L2 control signal, is allocated a resource (SB#1) that is closer on the time axis to the resource (LB#1), which the L1/L2 control signal is allocated, within the same frequency band as the L1/L2 control signal. A reference signal for CQI estimation, independent of a data signal and a L1/L2 control signal, is allocated a resource with which at least one of a reference signal for demodulation of a data signal and a reference signal for demodulation of a L1/L2 control signal is not transmitted at the same timing within the transmission band. The types of bandwidths of the reference signals multiplexed in a same short block within a same band are reduced, whereby restrictions as to the number of reference signal sequences that can be secured are diminished.