General binary tree protocol for coping with the capture effect in RFID tag identification

Tag anti-collision is an important issue in RFID systems because the reader must recognize all tags efficiently. In RFID wireless communication systems, tag identification will encounter the capture effect, where a reader decodes a tag ID even when multiple tags simultaneously transmit their signals. This letter proposes a tag anti-collision algorithm - the generalized binary tree protocol (GBT). GBT separates the identification process into several binary tree (BT) cycles to solve the problem caused by the capture effect. Unrecognized tags, hidden by the capture effect in a BT cycle, will be identified in subsequent cycles. The formal analysis of identification delay for GBT is derived and simulation and analytical results show that GBT significantly outperforms other existing algorithms.