Design bottlenecks of TC & TM spread spectrum links in UAVs

In this paper, we propose a structure for communicating TC and TM data streams in up and down links, respectively. Then we discuss about some bottlenecks which have been resolved in our structure. These bottlenecks are produced because of using spread spectrum technique and presence of Doppler frequency. The proposed method for synchronization has solved complexities of demodulation of SS signals due to requirements of precise synchronization, picking up accurate carrier and very low SNR. Then our method can de-spread signal in low SNR and high frequency offset. Techniques employed in design, optimize the receiver and the results of simulation show that synchronization was successful.