RFID reader capable of increasing forward anti-interference function

Abstract

The invention provides a RFID reader capable of increasing forward anti-interference function. A forward link includes an encoding module, a waveform generation module, a filtering module and a DAC. The filtering module is a Raised Cosine Filter which is implemented by look-up table in a FPGA. The method for implementing the Raised Cosine Filter includes the following steps: 1. on the basis of the modulation method of a RFID reader and the rate of outputting a baseband signal by the encoding module, taking a corresponding a step value from a step value ROM table; 2. if the rising edge or falling edge of forward data which is output by the waveform generation module is detected, starting to look up a filtering parameter ROM table, acquiring a filtering parameter, wherein the step value is one look-up parameter in the filtering parameter ROM table; and 3. on the basis of filtering parameter, setting the Raised Cosine Filter. According to the invention, the RFID reader has the characteristics of reduced bandwidth of baseband signals, sufficient capability of channel transmission, and reduced intersymbol interference.

Description

technical field [0001] The invention belongs to the field of RFID readers, in particular to an RFID reader with improved forward anti-jamming function. Background technique [0002] An RFID reader is a device for reading and writing tags in an RFID system. The interaction process with tags is divided into forward link and reverse link. Corresponding to the data sent from the reader to the tag and the tag sending data to the reader respectively. The forward link processing flow is as follows figure 1 As shown, the encoding module encodes the data to be sent according to certain encoding rules (such as PIE encoding, TPP encoding, FM0 encoding, etc.), and then the waveform generation module corresponds the encoded high and low levels (1 and 0) to the DAC required Code value, DAC converts the digital code into an analog waveform, and the radio frequency part modulates the baseband signal and sends it to the tag through the antenna. [0003] Among them, the encoded baseband s...

AI Technical Summary

Problems solved by technology

The forward filter adopted by the existing reader is a two-stage rectangular FIR+CIC filtering method, the adjustment range of the filter parameters is small, and it takes up more logic resources at the same time

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