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IEEE 802.16e wireless metropolitan area networks refers to the new standard for broadband wireless access (BWA), which targets to support wireless Internet service up to 2 Mbps. Existing draft version of standard proposes OFDM(A)-based handover process system, which consists of network topology acquisition, scanning, initial ranging, authorization, and(More)
IEEE 802.15.4 Low Rate Wireless Personal Area Network (LR-WPAN) is developed for emerging applications for industrial automation, home networking, wireless sensor networks, etc. In this paper, we propose a new scheme to enhance IEEE 802.15.4 in order to enable the fast delivery of packets, which announce the emergent situations or events of the network.(More)
In this paper, ranging process in IEEE 802.16e OFDMA systems is analyzed and performance is evaluated. Ranging process provides initial network entry, uplink synchronization, and system coordination. In the system initialization state, multiple users transmit randomly selected ranging code set and BS conducts multiple user identification by ranging code(More)
  • Doo Hwan Lee
  • 2005
For uplink synchronization, IEEE 802.16e wireless metropolitan area networks group has suggested ranging for OFDMA based uplink system. However, it is inherently vulnerable to the channel selectivity and other users' interferences at low SNR. In this paper, a novel detection scheme for OFDMA ranging has been proposed using modified generalized chirp-like(More)
Ranging process is proposed for the coordination between mobile station and base station in IEEE 802.16e OFDMA systems. It consists of ranging detection process (RDP), uplink resource allocation, and registration. Among them, RDP is the first step of ranging process and the core of wireless access algorithm in IEEE 802.16e OFDMA systems. Thus, it is(More)
— Random access process of LTE (long term evolution) system is carried out exploiting the superior correlation property of random access code. Each user unit transmits randomly selected random access code, and the Node B (base station) detects each code by correlating the received signal with all possible random access codes. By comparing the correlation(More)
— This paper considers the ranging process of IEEE 802.16 system in relay system. An interference problem between MS-BS ranging (i.e. ranging between mobile station and base station) and MS-RS ranging (i.e. ranging between mobile station and relay station), which is caused by the introduction of relay systems, is addressed. A solution of the interference(More)