A Review on Cooperative Communication Protocols in Wireless World

Future generations of cellular communications requires higher data rates and a more reliable transmission link with the growth of multimedia services, while keeping satisfactory quality of service, . MIMO antenna systems have been considered as an efficient approach to address these demands by offering significant multiplexing and diversity gains over single antenna systems without increasing bandwidth and power. Although MIMO systems can unfold their huge benefit in cellular base stations, but they may face limitations when it comes to their deployment in mobile handsets. To overcome this drawback, relays (fixed or mobile terminals) can cooperate to improve the overall system performance in cellular networks. Cooperative communications can efficiently combat the severity of fading and shadowing through the assistance of relays. It has been found that using relays the capacity and coverage of cellular networks can be extended without increasing mobile transmit power or demanding extra bandwidth.