Decode-and-forward relaying based on orthogonal complementary codes

KIZILIRMAK, Refik Çağlar

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access interference (MAI) between the user and relay. The orthogonal complementary codes have perfect autocorrelation and cross-correlation properties that provide MAI-free operation in asynchronous channels. ...Daha fazlası

Makale 2015 1 Görüntülenme

Effective 3D Surface Modeling for Geographic Information Systems

MENDİ, Engin | ALPARSLAN, Mesut | YÜKSEK, Kemal

Abstract. In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron st ...Daha fazlası

Makale 2016 Copernicus Gesellschaft Mbh 5 Görüntülenme