| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 94 === Abstract
Radio frequency identification (RFID) is an up-and-coming technology that will be used in several different areas in a few years, especially in the retail market, where the competition is fierce and cost reduction is the holy mantra. RFID is one of the several technologies where the goal is to automatically identify goods with as little human intervention as possible. The subject of this thesis is to enhance the added -value of increasing function competition, especially flexible protocol design is suitable for many applications at infinite distance.
The major content of this thesis discusses a more improved function than traditional active RFID. The traditional RFID uses a fixed communication model for a limited distance, in this thesis we use the ZigBee’s protocol to improve the communication model for much longer transmit distance via star & mesh network.
In this thesis, we use the IC JN5121 developed by vendor JENNIC, the process of this chip is a standard 0.18μm RFCMOS process, this chip contains a 32-Bit RISC CPU, 64k bytes of ROM and 96k Bytes of RAM. After the IEEE802.15.4 MAC and a flexible protocol are loaded into the IC JN5121, the chip can be used as the network infrastructure.
The baseband passes to the spreading function which maps each unique 4-bit symbol to a 32-chip Pseudo-random Noise (PN) sequence. QPSK modulation and half-sine pulse shaping is applied to the resultant spreading sequence to produce two independent quadrature phase signals, I and Q. These modulated baseband signals are subsequently converted to an analogue voltage in the radio transmit path.
This thesis uses the merits of ZigBee module of low power consumption, over 65K node, and more flexible IP function. So we can extend the detection distance unlimitedly and modify the protocol on line. I believe this thesis will be more useful in the real world, not only in the retailed market but also useful in the worst circumstance as passage access control.
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