Sidelink Subframe Symbol Mapping for AGC Reliability
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Solution Overview
Problem
Current vehicle-to-everything (V2X) and device-to-device (D2D) communication technologies face performance degradation due to automatic gain control (AGC) issues, where receivers fail to receive information during the first symbol of a sidelink subframe, leading to similar performance issues as puncturing.
Innovation Solution
The solution involves a transmitting device that maps complex valued symbols to physical resource blocks for sidelink transmission, excluding resource elements in the first symbol of a subframe, thereby avoiding performance degradation and ensuring accurate reception by not including information in this symbol, and also reserving the last symbol for rate matching to improve coverage and coding gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex valued symbols are mapped to all resource elements in a subframe including the first symbol, then resource utilization is maximized, but AGC performance degrades and information reception fails
Solution Approach 1:
The patent extracts the first symbol from the resource elements used for mapping complex valued symbols. By excluding the first symbol of each subframe from the mapping process, the system ensures that AGC can perform accurately on this symbol without interference from data transmission, while still utilizing all other symbols for efficient resource usage.
Solution Approach 2:
The patent applies different quality requirements to different parts of the subframe. The first symbol is reserved with high quality for AGC operation (no data mapping), while the remaining symbols are used for data transmission with standard quality requirements, creating a localized quality distinction that resolves the contradiction.
2Productivity
If the first symbol is used for data transmission, then resource efficiency improves, but AGC convergence fails and coverage is reduced
Solution Approach 1:
The patent performs preliminary action by reserving the first symbol for AGC operation before data transmission begins. This ensures that the receiver can establish accurate gain control in advance, creating a stable foundation for subsequent data reception and improving overall system reliability.
3Productivity
If all symbols are used for sidelink transmission, then transmission capacity increases, but coding gain and coverage are reduced
Solution Approach 1:
The first symbol acts as an intermediary between the physical transmission medium and the data transmission process. It provides a dedicated AGC adjustment period that mediates the transition from signal acquisition to reliable data reception, enabling better coding gain and coverage without significantly reducing overall transmission capacity.
Data Source
AI summary
A transmitting device maps complex valued symbols in sequence to physical resource blocks for a sidelink transmission. The transmitting device reserves a first symbol of a subframe, where resource elements in the first symbol of the subframe are not considered in mapping the complex valued symbols to the physical resource blocks for the sidelink transmission. The transmitting device transmits the sidelink transmission after mapping the complex valued symbols to the physical resource blocks. A receiving device receives the sidelink transmission and decodes the sidelink transmission to determine complex valued symbols that are mapped in sequence to physical resource blocks of the sidelink transmission, where the complex valued symbols are not mapped to resource elements in a first symbol of a subframe.