Full-Duplex Self-Interference Cancellation Power Control
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Solution Overview
Problem
Full-duplex radio communication systems face challenges in power control and link adaptation due to self-interference, which affects the successful decoding of desired signals and cyclic redundancy check (CRC) in wireless communication systems like LTE, leading to inefficiencies and potential interference with neighboring cells.
Innovation Solution
A method and apparatus for self-interference cancellation in a network node that receives a desired signal, performs cancellation using the same radio resource, determines the success of cancellation, and adjusts power control and link adaptation based on the outcome, including reducing transmit power when cancellation fails and increasing modulation and coding schemes when successful.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex radio communication is implemented to improve spectral efficiency and system capacity, then productivity is improved, but self-interference occurs that deteriorates signal quality and decoding accuracy
Solution Approach 1:
The patent applies self-interference cancellation techniques that convert the harmful self-interference signal into a beneficial component by estimating and subtracting the interference from the received signal. This allows the system to maintain full-duplex operation while eliminating the detrimental effects of self-interference on signal quality and decoding accuracy.
Solution Approach 2:
The patent implements preliminary self-interference cancellation before signal decoding by estimating the self-interference component based on known transmit signals and channel characteristics, and subtracting it from the received signal in advance. This preliminary anti-action prevents the interference from affecting subsequent decoding operations.
2Reliability
If transmit power is increased to improve signal quality and overcome interference, then reliability is improved, but power consumption increases and interference with neighboring cells worsens
Solution Approach 1:
The patent implements feedback-based power control where the receiver measures signal quality metrics (such as SINR or BER) and feeds back information to the transmitter. The transmitter then adjusts its transmit power based on this feedback to maintain reliable communication at the minimum necessary power level, avoiding excessive interference to neighboring cells.
Solution Approach 2:
The patent employs dynamic power adjustment mechanisms that continuously adapt transmit power levels based on real-time channel conditions, interference levels, and quality of service requirements. This dynamic approach allows the system to maintain signal quality when needed while reducing power and interference under favorable conditions.
3Reliability
If self-interference cancellation is performed to improve signal quality, then reliability is improved, but system complexity increases due to additional processing requirements
Solution Approach 1:
The patent divides the self-interference cancellation process into distinct segments or stages: channel estimation, interference signal generation, interference subtraction, and residual interference handling. This segmentation allows each component to be optimized independently and facilitates implementation using existing signal processing blocks in the receiver.
Solution Approach 2:
The patent designs the self-interference cancellation mechanism to leverage existing multi-functional components in the receiver, such as using the same channel estimation algorithms for both data detection and interference cancellation, and reusing signal processing pipelines for multiple purposes, thereby reducing overall system complexity.
4Reliability
If link adaptation is adjusted dynamically to overcome self-interference, then reliability is improved, but processing time and system complexity increase
Solution Approach 1:
The patent performs preliminary link adaptation adjustments based on predicted channel conditions and historical performance data before actual transmission occurs. By anticipating required adaptations in advance, the system reduces the need for time-consuming real-time adjustments and maintains reliable communication more efficiently.
Data Source
AI summary
Disclosed herein is method of performing self-interference cancellation in the network nodes supporting full-duplex communication. Specifically, the method includes receiving a desired signal from a user equipment (UE), performing cancellation of self-interference according to a transmitted signal of the network node, the transmitted signal using the same radio resource as the desired signal, determining whether the cancellation of the self-interference is successful, performing, upon determining that the cancellation of the self-interference is successful, decoding of the desired signal and checking cyclic redundancy check (CRC), and performing power control and link adaptation depending on success in performing the cancellation of the self-interference and a result of checking the CRC.