Distributed Exciter Network for RFID Interrogation Space Control
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Solution Overview
Problem
RFID systems face challenges in detecting signals in environments with low signal-to-noise ratios and high interference, particularly in identifying the location of RFID tags within interrogation spaces using distributed exciter architectures.
Innovation Solution
The implementation of a distributed exciter architecture with RFID receiver systems that control and manage multiple exciters to create interrogation spaces, using wireless or wired connections, and employing statistical analysis and sensor data to differentiate between true and false reads by comparing predicted and actual detection rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a distributed exciter architecture is used to extend RFID coverage area, then the interrogation space can be expanded to distant locations, but the system complexity increases due to multiple exciters requiring coordination and control
Solution Approach 1:
The system divides the large interrogation space into multiple smaller interrogation spaces, each covered by a separate exciter. The RFID reader controls multiple exciters (e.g., exciter 1, exciter 2) that each illuminate their own designated interrogation spaces. This segmentation allows the system to achieve wide coverage while maintaining manageable complexity by treating each exciter as an independent unit with defined responsibilities.
2Reliability
If multiple exciters are deployed to cover different interrogation spaces, then detection coverage is improved, but false reads increase due to signal interference between exciters
Solution Approach 1:
The system employs periodic time-division multiplexing where exciters are activated in alternating time slots. For example, exciter 1 is activated during time slot 1 to illuminate its interrogation space, then exciter 2 is activated during time slot 2. This periodic activation ensures that only one exciter transmits at a time, eliminating signal interference and false reads while maintaining comprehensive detection coverage across all interrogation spaces.
Solution Approach 2:
The RFID reader receives feedback signals from tags in each interrogation space and uses this information to control which exciters are activated. The system monitors detection results and adjusts exciter activation accordingly, enabling intelligent coordination that prevents interference while maximizing detection reliability across the distributed network.
3Measurement precision
If statistical analysis and sensor data are used to differentiate true and false reads, then detection accuracy is improved, but processing time and computational requirements increase
Solution Approach 1:
The system performs preliminary actions by pre-establishing the periodic activation schedule for exciters and pre-defining the interrogation spaces each exciter is responsible for. By organizing the exciter activation pattern in advance and using time-division multiplexing, the system eliminates the need for complex real-time statistical analysis to differentiate true and false reads, as the periodic structure inherently prevents interference-related false reads.
Data Source
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AI summary
RFID systems are disclosed that include at least one RFID receiver system and a distributed exciter architecture. The exciters can be connected via wired and/or wireless connections to the RFID receiver system and the RFID receiver system can control the activation of the exciters to detect the presence of RFID tags within interrogation spaces defined by the exciter topology. In several embodiments, the RFID receiver system performs location estimation to determine the interrogation space in which a specific RFID tag or collection of RFID tags is located. One embodiment of the invention includes an RFID receiver system configured to detect information from RFID tags within a receive coverage area, and a plurality of exciters defining a plurality of interrogation spaces within the receive coverage area of the RFID receiver system. In addition, the RFID receiver system is configured to transmit a control signal that identifies one of the plurality of exciters and includes information indicative of an RFID tag interrogation signal, the plurality of exciters are configured to receive the control signal, and the exciter identified in the control signal is configured to illuminate an interrogation space with the RFID tag interrogation signal.