Recently, attention of geolocation system is increased on civil purpose. Various location applications, i.e. Navigation, Enhanced 911, mobile advertising, asset tracking, fleet management etc., are developed and serviced. However, the geolocation system is originally developed and performed in military. It is well known that the Global Positioning System (GPS) is currently employed for field operations. However, the GPS can be affected by the weather condition or the lay of the land, and the terminal consumes the plenty of power. Thus, we propose a location system based on a local military tactical network in order to assist the GPS.
The location finding system can be classified as 3 Base-Station (BS), 2BS, 1BS system according to the minimum number of the required BSs. The BS in local military tactical network has mobility and limitations on scalability. Due to these properties, 1 BS system is considered. Also, the military operations need the identification of multiple units. Hence, we propose a multi-user location finding system based on 1 BS system.
The OFDMA system has been a promising technique in multi-user system, which is adopted in some standards such as IEEE 802.16e Mobile WiMAX (WiBro). Moreover, the Korean Army exploits Tactical Information Communication Network (TICN) based on WiBro system. Therefore, we propose a multi-user location finding system based on WiBro OFDMA.
The proposed system is composed of a BS with multiple array antennas and multiple mobile stations (MSs) with single antenna. The system estimates multiple AOAs and ranging information simultaneously utilizing uplink Advanced Antenna Systems (AAS) preamble. Since it has to estimate the entire user at the same time, the complexity of the system has to be considered. we adopt Matrix Pencil algorithm, which is well known for its lower complexity than other method, for Angle of Arrival(AOA). The Received Signal Strength Indication (RSSI) is selected for ranging because it is easy ...