Distributed Space-Time Coding in Cooperative Communication Systems

Different types of schemes in previous work have been studied and displayed that spatial diversity can be achieved at the network. MIMO system uses multiple antennas at both the transmitter and receiver to attain spatial diversity. Nevertheless, MIMO system needs multi-antennas terminals, which may be unfeasible in small terminals due to the size, power consideration for user's terminals and the spacing between adjusted antennas should be longer than a half wavelength to keep all the channels uncorrelated. Thus the idea of cooperative diversity has been recommended to offer spatial diversity with single antenna terminals, it is also imperative to adapt the routing scheme to incorporate the requirement for multiple paths between nodes. Cooperative communication systems are considered to be a promising technology to improve the system capacity, reliability and performance over fading wireless channels. A cooperative relaying system with relay nodes will be able to obtain the advantages of multiple antenna communication systems. Cooperative techniques are ideally suitable for the distributed communication systems.