Preamble Design and Synchronization Algorithm for Cooperative Relay Systems

In the cooperative relay system, different frames from different relays are not aligned in the time domain, and have different carrier frequency offsets (CFOs). Estimation of these time offsets and multiple CFOs is a crucial and challenging task. In this contribution, a new preamble structure is proposed, and the corresponding timing and frequency synchronization algorithms are also presented for the cooperative relay systems. CAZAC sequence is utilized in the preamble design regarding of its correlation properties. The performance of the proposed algorithms is evaluated by simulations. The simulation results show that the proposed preamble structure and synchronization algorithms have a satisfactory performance in cooperative relay systems.