Multi-user space-time coding in cooperative networks

Multiple antennas at the receiver and transmitter are often used to combat the effects of fading in wireless communication systems. However, implementing multiple antennas at mobile stations is impractical for most wireless applications due to the limited size of the mobile unit. We emulate spatial diversity using mobile relay stations, which cooperate by retransmitting the information received from a mobile station to a destination station. We propose an Alamouti based cooperative system with two relay stations and we provide an approximate formula for the average symbol error probability of this system in a Rayleigh fading environment.