Dual-Frequency EPC Gen2 Decoder for UHF RFID Precision Power Trade-off
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Solution Overview
Problem
Existing methods for measuring the length of the TRcal symbol in EPC Class-1 Generation-2 UHF RFID systems face challenges in achieving precision while minimizing power consumption and ease of implementation, as higher oscillator frequencies improve precision but increase power consumption, and alternative methods lack robustness and ease of implementation.
Innovation Solution
A dual-frequency EPC Gen2 Decoder that uses high frequency (2.56 MHz or 1.92 MHz) for precise TRcal symbol measurement and low frequency (1.28 MHz) for decoding other symbols, optimizing power consumption while maintaining robustness and ease of implementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high frequency oscillator (1.92 MHz or higher) is used for timer based method, then measurement precision of TRcal symbol length is improved, but power consumption increases
Solution Approach 1:
The patent applies dynamics by making the clock frequency adjustable rather than fixed. The oscillator frequency is dynamically changed based on the operational phase: high frequency (1.92 MHz or higher) during TRcal symbol measurement for precision, and low frequency during other operations for power savings. This temporal variation in system parameters resolves the contradiction between precision and power consumption.
Solution Approach 2:
The patent changes the physical parameter of oscillator frequency according to operational requirements. By switching between high frequency (for precise TRcal measurement) and low frequency (for power-efficient other operations), the system optimizes the trade-off between measurement precision and power consumption without compromising either requirement.
2Use of energy by moving object
If alternative dynamically calibrated methods are used, then power consumption is reduced, but robustness and ease of implementation deteriorate
Solution Approach 1:
The patent segments the operational phases and applies different clock frequencies to different segments: high frequency for the critical TRcal measurement segment and low frequency for other segments. This segmentation allows the system to maintain robustness during critical operations while achieving power savings during less critical operations, unlike alternative methods that compromise robustness across all operations.
3Measurement precision
If a single high frequency decoder is used, then TRcal symbol measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic action by alternating between high and low clock frequencies based on the operational phase. The high frequency is periodically activated only during TRcal symbol measurement, while low frequency is used during other phases. This periodic switching resolves the contradiction by providing high precision only when necessary and saving power during other operations.
Data Source
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AI summary
The invention concerns a method and device (1) for processing UHF signals for an EPC communication. The method includes the steps of picking up UHF signals by an antenna (2) of the device (1) for processing UHF signals, creating an envelope signal from the UHF signals picked by the antenna (2) in a demodulator (3), processing the envelope signal and decoding critical TRcal symbol and data in a logic unit (5) of the device (1). Furthermore, the method includes the steps of interpreting the critical TRcal symbol and data, storing the interpreted data, encoding transmit data, modulating by encoded data in a modulator (4), and clocking the steps as above by a local oscillator (9). In the step of processing the envelope signal, the critical TRcal symbol is processed by a high frequency clock and data are processed by a low frequency clock.