Design of distributed space-time trellis code for relay systems over cascaded Nakagami channels

In this paper, error performance of a coded cooperative relay system is investigated when channels have cascaded Nakagami distribution. By using general pairwise error probability upper bound of the system, code design criterion for the distributed space-time code is derived and using this criterion, 8-state distributed space-time trellis codes for 4-PSK and 8-PSK modulations are designed. The error performances of the new codes are evaluated by computer simulations and compared those of the corresponding codes.