Zero Power Subcarrier Allocation for Inter-Numerology Interference Reduction
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Solution Overview
Problem
In 5G communication systems, the coexistence of multiple numerologies leads to inter-numerology interference, which affects channel estimation quality and decoding accuracy, making it challenging to coordinate the transmission of reference signals and data across different numerologies.
Innovation Solution
A transmission device allocates zero power to specific subcarriers between numerologies, ensuring no transmit power is assigned to certain resource elements, thereby reducing inter-numerology interference by configuring zero power resource elements specifically for each numerology, allowing for orthogonal subcarrier allocation and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple numerologies are used to support diverse 5G services, then service flexibility and adaptability are improved, but inter-numerology interference increases affecting channel estimation and decoding
Solution Approach 1:
The frequency spectrum is segmented into different numerology-specific resource pools, where each numerology (e.g., 15kHz, 30kHz, 60kHz subcarrier spacing) is allocated dedicated subcarrier sets. This segmentation prevents overlapping transmissions between different numerologies, eliminating inter-numerology interference while maintaining support for diverse services like eMBB, URLLC, and mMTC.
Solution Approach 2:
Different quality characteristics are assigned to different frequency regions based on service requirements. Critical services like URLLC are allocated numerologies with larger subcarrier spacing (e.g., 60kHz) for lower latency, while eMBB uses 15kHz or 30kHz for higher throughput. Each numerology's resource elements are optimized locally for its specific service type, improving overall system adaptability.
2Measurement precision
If zero power allocation is applied to reduce inter-numerology interference, then channel estimation accuracy is improved, but resource utilization efficiency decreases
Solution Approach 1:
Reference signal resources are extracted and isolated into dedicated resource elements within each numerology's allocated frequency range. By separating reference signals from data transmission resources and assigning them to specific numerology slots, the system enables accurate channel estimation without requiring zero-power allocations, thus maintaining high resource utilization.
Solution Approach 2:
Channel estimation is performed preliminarily using reference signals transmitted before data transmission in each numerology's time-frequency grid. This preliminary channel state information is then used to pre-condition the data detection process, improving accuracy without needing to waste resources on repeated estimation attempts or zero-power protective allocations.
Data Source
AI summary
An integrated circuit includes control circuitry and transmitting circuitry. The control circuitry maps data or a reference signal onto resources including orthogonal subcarriers of a first numerology and a second numerology, which differ at least by subcarrier spacing and are frequency-multiplexed on a subcarrier basis. The control circuitry assigns no transmit power to at least one subcarrier located between a subcarrier of the first numerology and a subcarrier of the second numerology. The subcarriers of the second numerology include: inter-numerology-orthogonal subcarriers, each of which is centrally aligned with a subcarrier of the first numerology, and non-inter-numerology-orthogonal subcarriers not centrally aligned with any subcarrier of the first numerology and located between two adjacent subcarriers of the first numerology. The control circuitry assigns no transmit power to at least one of the non-inter-numerology-orthogonal subcarriers. The transmitting circuitry transmits the mapped data or reference signal.