Full-Duplex Radio Mode Switching for Residual Interference Control
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Solution Overview
Problem
Self-interference occurs in full duplex radio systems, reducing reception performance despite existing technologies to mitigate it, leading to residual interference.
Innovation Solution
A method is introduced to discriminate between full and half-duplex services, switching transmission modes based on channel quality indicators, modulation and coding schemes, and timing advance values to optimize data transmission and reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex transmission mode is used to improve spectral efficiency and system capacity, then productivity increases, but self-interference occurs which degrades reception performance and reliability
Solution Approach 1:
The patent implements dynamic switching between full-duplex and half-duplex transmission modes based on real-time channel conditions, CQI feedback, and interference levels. This allows the system to adaptively optimize spectral efficiency while maintaining reception performance by transitioning to half-duplex mode when self-interference becomes problematic.
Solution Approach 2:
The system changes transmission parameters including modulation and coding scheme (MCS) selection, timing advance values, and mode switching based on CQI information and measured interference levels. These parameter adjustments allow the system to operate in full-duplex mode with optimal performance or switch to half-duplex when necessary.
2Productivity
If full-duplex mode operates continuously to maximize throughput, then productivity increases, but residual self-interference degrades reception quality and reliability
Solution Approach 1:
The patent employs feedback mechanisms where the UE reports CQI information and ACK/NACK status to the BS. The BS uses this feedback to monitor reception quality and dynamically adjust transmission mode, switching from full-duplex to half-duplex when consecutive NACKs indicate degradation in reception quality.
Solution Approach 2:
The system uses its own transmitted signals as reference for self-interference cancellation and channel estimation. By utilizing the known transmitted waveform, the system can identify and subtract self-interference components from received signals, improving reception quality while maintaining full-duplex operation.
3Reliability
If transmission mode switching is implemented to maintain reception performance, then reliability improves, but system complexity increases due to additional control mechanisms
Solution Approach 1:
The patent segments the transmission mode control into distinct decision criteria: CQI threshold comparison, consecutive NACK counting, and timing advance verification. Each criterion operates independently to trigger mode switching, simplifying the overall control logic while maintaining reliable reception performance.
Solution Approach 2:
The system leverages existing uplink control channels (PUCCH, PUSCH) and feedback mechanisms (CQI, ACK/NACK) that are already part of the standard protocol stack. By reusing these existing structures for mode switching decisions, the patent avoids adding significant control overhead or complexity while achieving reliable reception.
4Productivity
If mode switching based on CQI and timing advance is used to optimize performance, then productivity is maintained, but the complexity of detecting and measuring optimal switch points increases
Solution Approach 1:
The system uses the UE's own CQI reports and timing advance measurements, which are already being generated for normal operation, to trigger mode switching. This self-service approach uses existing measurement infrastructure without requiring additional complex detection mechanisms, maintaining productivity while avoiding increased measurement complexity.
Data Source
AI summary
The present document relates to a method by which a base station transmits and receives data in a wireless communication system, and discloses a method for transmitting and receiving data, the method comprising the steps of: receiving channel quality indicator (CQI) information from user equipment; selecting a first modulation and coding scheme (MCS) level from among one or more MCS levels on the basis of the CQI information; transmitting, to the user equipment, data to which the selected first MCS level is applied, in a full-duplex (FD) transmission mode; receiving, from the user equipment, acknowledge/negative acknowledgement (ACK/NACK) for the transmitted data; and determining whether or not to switch the transmission mode, wherein the switching of the transmission mode is determined on the basis of at least one of a predetermined number of consecutive NACKs, a mode switch threshold, and the one or more MCS levels.