A WIMAX MIMO Network Architecture Exploiting Spatial Diversity of Multiple Antenna Sites

This paper presents a framework to exploit the Multi Input Multi Output (MIMO) technique in the Worldwide Interoperability for Microwave Access (WIMAX) physical layer. MIMO is an established standard in the WIMAX family, however practical literature on the exploitation of MIMO in WIMAX networks focused on treating the paradoxical situation of demand for Line Of Sight (LOS) in microwave communications against the essential MIMO prerequisite, i.e., the Non LOS (NLOS) and multi fade paths. This framework proposes a novel approach to exploit potentials of MIMO in WIMAX networks. This is achieved by exploiting spatial diversity of Multiple Antenna Sites (MAS) to create artificial NLOS environment, whereby, MAS(s) are encapsulated as antennas in a large scale frame. This presents a significant enhancement of the existing schemes, which highlighted the exploitation of the combination of Time Division Duplexing (TDD), Orthogonal Frequency Division Multiplexing (OFDM), and MIMO for Multiple Access Points (MAP(s)) in a Single Frequency Network (SFN). In this paper, the network is divided into layers and the above exploitation of MIMO is realised between these layers in a network-to-network communication scenario. The resulting network is characterized by high capacities at distribution access points and ease of design by virtue of combination of SFN and spatial techniques.