Performance Analysis of Mixed MIMO-RF/MIMO-FSO DF Relaying Using Globally Coupled Low Density Parity Check (GC-LDPC) Codes and Diversity Techniques

This article focuses on the performance analysis of cooperative systems hybridizing MIMO-RF/MIMO-FSO and error correcting codes including GC-LDPC codes in FSOs. In this double-hop relay system composed of links with several inputs and multiple outputs at radio frequency and with multiple inputs and multiple outputs in FSO. In this system the source transmits the information to the relay by RF links, the relay processes the information received from the source and retransmits it to the destination by FSO links. To decode the data we used two-phase local-global decoding and to eliminate interference between source-relay links and relay-destination links we use interference alignment (IA) technique. It is also assumed that the source-relay link undergoes Rayleigh fading, while the relay-destination links undergo Gamma-Gamma model fading. Using DF relay technology, hybrid MIMO-RF/MIMO-FSO systems combine the advantages of RF and FSO communication technologies. The use of hybrid MIMO- RF/MIMO-FSO cooperative transmission systems improves network reliability and transmission. In this work, we carried out a simulation study on the distribution of the total transmission power at the source and the relay level to understand the best allocations between the source and the relay in order to guarantee a good quality of reception of the data transmitted to the destination. This work also presents studies on the different combimaision techniques. The results of our simulations show that the MIMO-RF/MIMO-FSO system based on GC-LDPC codes gives better performance compared to MIMO-RF/FSO and RF/FSO systems based on the same codes but also with conventional systems without the use of codes.