A Study on Cell Search Algorithms for IEEE 802.16e OFDMA Systems

In this paper, the problem of cell search for IEEE 802.16e OFDMA systems is addressed, which includes two steps: frame detection and cell ID identification. We propose two novel frame detection algorithms: one is based on the pseudo-periodicity property of the preamble signal in time-domain (TD algorithm), and the other one is based on the Euclidean distance in frequency-domain (FD algorithm). In comparison with the FD algorithm, the TD algorithm is more robust to fading and interference, at the cost of a higher implementation complexity. Therefore, we should choose the suitable one based on different system reliability and complexity requirements. As for the cell ID identification procedure, an adaptive correlation length algorithm (ACL algorithm) is proposed, in which the necessary correlation length can be chosen without prior channel knowledge, and thereby greatly reduces the cell search time. The system simulation results show that the proposed frame detection and cell ID identification algorithms are robust and efficient for OFDMA cellular systems, especially for IEEE 802.16e OFDMA systems.