Implementation and extension of a GNU-Radio RFID reader

[摘要] The development of a flexible software defined RFID is discused. Commercial reader systemsonly allow a top level view on the communication andrestrict the variation for many transmission parameters.Recently a software reader from the CGran project was proposed which uses the GNU Radio environment in combination with anUSRP front end. Because most of the signal processing is done on a common host PC, this reader offers high flexibility,but also has several disadvantages. One of the main hardware limitations is the usage of only one separatedantenna per transmit and receive path. Commercial readers usually use four antennas which are time multiplexed and can be usedas transmitter and receiver. In this work a HF multiplexer for the USRP device is introduced. With this extension up to four transmit andreceive antennas can be used in combination with the software reader. It is shown that the multiplexerachieves good readrates for a switching interval of 100 ms. Using this multiplexer the read range of the systemdecrease compared to the basic software reader, but distances over two meters can still be realized without additionalhardware extensions.

[学科分类] 电子、光学、磁材料