Anti-Collision Technique of SAW Tags Using Walsh Code

Abstract

—In view of the inefficiency of coding, the complexity of signal extraction and the strict demands of machining in the existing multiple SAW tags system, an anti-collision technique based on Walsh Code was proposed. First, it encodes the 2PSK using the single antenna transmission structure, then it implements the orthogonal encoding of each tag in a multiple SAW tags system using Walsh coding, and finally the encoding information of each tag is acquired by reading the echo signals from the reader and doing cross-correlation operation with each code block in the orthogonal code-set. The proposed approach incorporates both the coding efficiency and the processing technology, simplifies the complexity of signal extraction, and achieves the goal of anti-collision of multiple SAW tags system. The theoretical analysis and simulation verify the feasibility of this technique.