Dual-Frequency Backscatter Signaling for Self-Interference Filtering
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Solution Overview
Problem
Existing communication systems face challenges in effectively eliminating self-interference in backscatter signals due to the use of single or multiple antennas, leading to increased hardware costs and reduced power efficiency, particularly in RFID systems.
Innovation Solution
A method involving the use of carrier signals with different frequencies to generate backscatter signals, allowing for the suppression of self-interference without additional hardware circuits by exploiting 3rd order intermodulation signals and utilizing band-pass filters to filter out unwanted signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single antenna connected to a circulator or directional coupler is used for FDD communication mode, then the system can perform frequency division duplex communication, but self-interference elimination becomes difficult and hardware complexity increases
Solution Approach 1:
The patent changes the frequency parameter by transmitting two carrier signals with different frequencies (first carrier signal and second carrier signal at different frequencies). This allows the system to perform FDD communication while enabling the receiving device to generate backscatter signals that can be differentiated from self-interference through frequency analysis, thus resolving the contradiction between FDD capability and self-interference elimination difficulty
Solution Approach 2:
The patent introduces an intermediary mechanism where the receiving device generates backscatter signals based on the received carrier signals. These backscatter signals serve as a mediator that carries information back to the transmitting device without requiring complex circulators or directional couplers, thereby reducing hardware complexity while maintaining FDD functionality
2Adaptability or versatility
If multiple antennas are used for simultaneous transmission and reception, then FDD communication mode can be achieved, but hardware cost increases
Solution Approach 1:
The patent makes the receiving device multi-functional by enabling it to both receive carrier signals and generate backscatter signals. This universal functionality allows a single receiving device to perform multiple roles, eliminating the need for multiple separate antennas and reducing hardware cost while maintaining FDD communication capability
Solution Approach 2:
The receiving device serves itself by generating backscatter signals autonomously based on the received carrier signals. This self-service mechanism eliminates the need for additional transmitting antennas, thereby reducing hardware quantity and cost while achieving simultaneous transmission and reception functionality
3Reliability
If traditional backscatter signal reception is used, then communication can be maintained, but power efficiency decreases
Solution Approach 1:
The receiving device autonomously generates backscatter signals without requiring additional power-intensive transmitting components. By leveraging the received carrier signals to create backscatter signals, the system maintains reliable communication while significantly improving power efficiency, as the receiving device performs both reception and signal generation functions
4Measurement precision
If self-interference is not effectively eliminated, then signal parsing success rate decreases, but additional hardware circuits increase cost
Solution Approach 1:
The patent uses frequency parameter changes to distinguish backscatter signals from self-interference. By transmitting carrier signals at different frequencies and analyzing the frequency characteristics of received signals, the system can effectively separate and parse backscatter signals without requiring additional interference elimination hardware circuits, thus improving signal parsing success rate while avoiding increased hardware cost
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the ability to filter out self-interference effectively, improving the success rate of backscatter signal parsing without increasing hardware costs, thereby maintaining power efficiency and reducing interference.
Implementation Method 1
sending, by a target communication device, a first carrier signal and a second carrier signal, where a frequency of the first carrier signal is different from a frequency of the second carrier signal
Implementation Method 2
the backscatter signal is obtained based on the first carrier signal and the second carrier signal
Data Source
AI summary
A signal transmission method and apparatus, and a communication device are disclosed relating to communication technologies. The signal transmission method according to embodiments of this application includes: sending, by a target communication device, a first carrier signal and a second carrier signal, where a frequency of the first carrier signal is different from a frequency of the second carrier signal; and receiving, by the target communication device, a backscatter signal, where the backscatter signal is obtained based on the first carrier signal and the second carrier signal.