5G Reference Signal Mapping to Stabilize DC Subcarrier Bandwidth
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Solution Overview
Problem
In future 5G systems, the dynamic change of DC subcarrier locations and quantities due to varying user equipment bandwidths complicates system design, leading to interference issues in data demodulation, especially when user equipment bandwidths are lower than base station bandwidths.
Innovation Solution
A data transceiving method that maps reference signals to specific subcarriers within a physical resource block, avoiding DC subcarriers and using idle subcarriers as DC subcarriers, allowing correct demodulation and reducing dynamic changes in downlink subcarrier quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an additional DC subcarrier is reserved at each DC subcarrier location to avoid interference, then data demodulation accuracy is improved, but system bandwidth becomes dynamic and resource index changes, increasing system design complexity
Solution Approach 1:
The patent extracts the DC subcarrier from the set of subcarriers used for data transmission. By explicitly excluding the DC subcarrier location from resource allocation, the system avoids mapping data to this interfering subcarrier while maintaining a fixed system bandwidth structure. This resolves the contradiction by removing the harmful element rather than adding compensatory elements.
Solution Approach 2:
Instead of adding an additional idle subcarrier to protect against DC interference (as in conventional LTE), the patent inverts the approach by directly excluding the DC subcarrier from the resource pool. This inversion simplifies the system design by working with the existing bandwidth structure rather than modifying it dynamically.
2Adaptability or versatility
If different user equipments are allocated different resources due to varying bandwidth capabilities, then adaptability to different devices is improved, but DC subcarrier locations become uncertain, causing dynamic bandwidth changes
Solution Approach 1:
The patent applies local quality by allowing different user equipments to access different subsets of subcarriers based on their bandwidth capabilities, while maintaining a consistent rule that the DC subcarrier location remains excluded from all allocations. This enables device adaptability without compromising system bandwidth stability.
Solution Approach 2:
The patent creates a universal resource allocation rule that applies to all user equipments regardless of their bandwidth capabilities. The DC subcarrier exclusion rule serves multiple functions: it prevents interference for all devices, maintains fixed bandwidth structure, and simplifies scheduling across diverse device types.
3Object-affected harmful factors
If no data is mapped to the DC subcarrier in LTE system, then interference avoidance is achieved, but resource utilization decreases as the DC subcarrier cannot be used for transmission
Solution Approach 1:
The patent extracts the DC subcarrier from the available resource pool and explicitly excludes it from data mapping. This prevents interference while clearly defining the remaining usable subcarriers, allowing maximum resource utilization within the constrained bandwidth structure.
Data Source
AI summary
A data transceiving method includes: receiving a first reference signal transmitted on a subcarrier in a target physical resource block, and performing, according to a first mapping rule, corresponding processing on the first reference signal received from the subcarrier in the target physical resource block, where the first mapping rule defines at least mapping of the first reference signal to 10 specified subcarriers in a physical resource block, none of the 10 specified subcarriers are in a DC subcarrier candidate set, and the first reference signal includes a PCRS. In the embodiments of this application, only the 10 specified subcarriers in the physical resource block that are not used as DC subcarriers are selected to transmit the first reference signal, and no additional DC subcarrier is set. In this way, a quantity of downlink subcarriers in a system does not change dynamically.