Carrier inhibiting method for radio frequency identification reader-writer and radio frequency device

Abstract

The invention relates to a carrier inhibiting method for a radio frequency identification reader-writer, which comprises the following steps of: processing a received signal to obtain two paths of orthogonal baseband signals, obtaining an initial phase valve and an amplitude valve of a cancelling signal by use of two paths of orthogonal baseband signals; carrying out iterative operation on the initial phase value of the cancelling signal to obtain a target phase valve of the cancelling signal; and generating the cancelling signal, and overlapping the cancelling signal to the received signal after modulation. The invention also relates to a radio frequency device of the radio frequency identification reader-writer. By implementing the carrier inhibiting method for the radio frequency identification reader-writer and the radio frequency device in the invention, the beneficial effect that the carrier of the reader-writer per se in a receiving channel can be effectively cancelled is achieved.

Description

technical field [0001] The invention relates to the field of radio frequency identification, more specifically, to a carrier suppression method and a radio frequency device for a radio frequency identification reader. Background technique [0002] Radio frequency identification is an identification technology that uses space-propagated electromagnetic waves for data exchange. The RFID system mainly consists of readers and tags. Readers obtain information by identifying tags. Depending on the type of tag, the recognition distance is also different. There are two types of existing tags: active tags and passive tags. Among them, passive tags are widely used due to their low cost and small size. However, since passive tags communicate by reflecting and modulating the carrier wave of the reader, they are susceptible to many interferences. These interferences include: the signal sent by the reader is phase noise for the receiving carrier, which is easily confused with the echo...

AI Technical Summary

Problems solved by technology

If the noise enters the receiving channel and is directly amplified, it will exceed the dynamic range of the receiver, causing the receiving channel to be blocked and the echo information cannot be correctly resolved

Therefore, eliminating or offsetting the carrier signal of the reader-writer as much as possible is a relatively key measure to achieve maximum sensitivity; however, there is no more effective way to eliminate or offset the carrier wave of the reader-writer when receiving in the prior art

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