Tag collision is a major problem in the field of multi-tag identification in RFID systems. To solve this problem, many RFID systems adopt their own collision arbitration algorithms based on framed-structure slotted Aloha (FSSA) due to the simplicity of implementation. The frame size, meaning the number of slots in a frame, is a very important factor to inventory tags' responses in the FSSA. How to assign the frame size is therefore crucial to the collision arbitration performance. Since the existing collision arbitration methods do not consider the slot times of each slot when assigning frame size, they may increase overall identification time. By involving the slot times, we improve the collision arbitration performance of the conventional methods. Simulation results show that collision arbitration based on the proposed method is superior to that based on the conventional methods, irrespective of the number of tags.

A power analysis attack is a well-known side-channel attack but the efficiency of the attack is frequently degraded by the existence of power components, irrelative to the encryption included in signals used for the attack. To enhance the performance of the power analysis attack, we propose a preprocessing method based on extracting encryption-related parts from the measured power signals. Experimental results show that the attacks with the preprocessed signals detect correct keys with much fewer signals, compared to the conventional power analysis attacks.

In this letter we propose a simple adaptive algorithm which solves the unit-norm constrained optimization problem. Instead of conventional parameter norm based normalization, the proposed algorithm incorporates single parameter normalization which is computationally much simpler. The simulation results illustrate that the proposed algorithm performs as good as conventional ones while being computationally simpler.

This paper proposes a novel method to suppress tag collision in the ISO 18000-6 type B protocol which is one of the standard protocols of UHF RFID systems. The anti-collision performance in terms of the total identification time is improved by reducing the length of bits and the number of transmission commands required for multi-tag identification in the ISO 18000-6 type B protocol. Simulation results show that the proposed method improves the multi-tag identification time by about 15% over the conventional method, irrespective of the number of tags.

This paper presents analysis results on finite-impulse response (FIR) channel estimation used for the equalization in Advanced Television Systems Committee digital television receivers. While channel estimation results have been effectively used for the equalization, the conditions of sufficient order and high signal-to-noise ratio (SNR) were assumed in most cases. To compensate for these unrealistic assumptions, we consider diverse probable conditions for channel estimation, such as reduced order and low SNRs, and then theoretically analyze each estimation case. The analysis shows that the adaptive FIR channel estimator provides an unbiased estimation and matches well its corresponding channel coefficients irrespective of the number of taps of the estimator and the non-causality of the unknown channel. Simulation results verify our analysis on the estimation of terrestrial DTV channels.