Cooperative Wireless Communications and Physical Layer Security: State-of-the-Art

One morning, we were waiting for our college bus. The Wipro industry bus was slowly passing nearby us looking for its employees. At the last moment, when the driver increased speed, one person stepped down from the auto rickshaw and shouted “stop the bus, stop the bus”. Voluntarily, whoever was present started shouting “stop, stop the bus”. The sound finally reached the bus driver who stopped the bus, and the employee could catch it in time. This analog from everyday realistic life simply depicts the spirit of cooperative wireless communication which utilizes the information overheard by neighbouring nodes to offer reliable communication between sender and receiver. Future converged wireless networks are expected to provide high data rate services with extension in coverage area. Also, the next generation networks should possess bandwidth efficiency, less power consumption ability with small sized mobile equipment. Multiple-input multiple-output (MIMO) system is the best technique for the provision of communication diversity wherein multiple antennas are installed at the sender and receiver. In today’s miniaturizing electronics era, the hardware implementation of MIMO in the mobile equipment is not feasible due to resource constraints. Cooperative wireless communication (CWC) is the upcoming virtual MIMO technique to combat fading and achieve diversity through user cooperation. Physical layer security (PLS) is the imminent security guarantee for the cooperative communication.