A Novel Computation Method for Tag Estimates in DFSA-based RFID Systems

Abstract

In this paper, we propose a novel computation method for tag estimation in the dynamic framed slotted ALOHA (DFSA) protocol, based on Vogt’s estimate (VE). The estimation target is system load λ and tag estimate N̂ is computed from the estimated values of λ, instead of the direct approach taken in the existing method. Starting from the definition of VE, we derive a single concise equation for the estimate. For the numerical solution, we present a load estimation algorithm, which turns out to be computationally very efficient. The computational complexity is roughly O(10 log<SUB>10</SUB> N<SUB>max</SUB>), in contrast to O(N<SUB>max</SUB>) in the existing method for maximum possible number of tags, N<SUB>max</SUB>. Through computer simulations, we show that the proposed method indeed yields estimation results almost identical to those by the existing method in most cases.