Backscatter Signal Scheduling to Avoid Zero-Power Self-Interference
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Solution Overview
Problem
In zero-power communication systems, self-interference occurs when a network device transmits a downlink signal and receives a backscattered signal from a zero-power terminal, causing interference that hampers data decoding due to the power imbalance between the network device and the zero-power terminal.
Innovation Solution
The communication method involves transmitting and receiving signals through channels and time domain positions that satisfy specific constraints, such as using separate channels for uplink and downlink transmissions and incorporating guard intervals, to avoid self-interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the network device transmits downlink signal and receives backscattered signal simultaneously in the same channel, then the system complexity is reduced, but self-interference occurs that hampers data decoding
Solution Approach 1:
The patent divides the channel into separate uplink and downlink channels, segmenting the communication resources to avoid self-interference. The network device transmits downlink signals in downlink channels while receiving backscattered signals in uplink channels, physically separating the interfering signals in the frequency domain.
Solution Approach 2:
The patent introduces frequency domain separation as an additional dimension for resource allocation. By assigning different frequency resources (channels) for uplink and downlink transmissions, the system resolves the interference problem by utilizing another dimension of the signal space.
2Productivity
If the network device uses the same channel for both downlink transmission and backscattered signal reception, then the channel resource utilization is improved, but self-interference causes power imbalance issues
Solution Approach 1:
The patent segments the available channel resources into distinct uplink and downlink channels, allocating specific frequency resources for each direction. This segmentation prevents the strong downlink transmission from overwhelming the weak backscattered signal reception in the same channel.
Solution Approach 2:
The patent introduces guard intervals as intermediary time resources between uplink and downlink transmissions. These guard intervals act as buffers that prevent direct interference while allowing efficient channel resource utilization through structured time-division multiplexing.
3Reliability
If guard intervals are incorporated to avoid self-interference, then the data decoding reliability is improved, but the time domain resource efficiency decreases
Solution Approach 1:
The patent applies preliminary actions by pre-configuring guard intervals and channel separation schemes before communication occurs. The network device预先 determines which channels are uplink and which are downlink, and inserts guard intervals at predetermined positions, preventing interference before it occurs rather than correcting it afterward.
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 reliability and robustness of backscattering communication by minimizing self-interference, ensuring effective data transmission and reception in zero-power communication systems.
Implementation Method 1
the terminal device transmits a second signal to the network device, the second signal being a backscattered signal of the first signal
Data Source
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AI summary
Embodiments of the present application provide a communication method and apparatus, a terminal device, and a network device. The method comprises: receiving, by a terminal device, a first signal sent by a network device and sending, by the terminal device, a second signal to the network device, wherein, the second signal is a backscatter signal of the first signal, a channel where the second signal is located satisfies a first constraint, and/or a time domain position where the second signal is located satisfies a second constraint.