Channel capacity and space-time block coding for coherent optical MIMO multi-mode fiber links

The capacity enhancement for random coherent optical multiple-input multiple-output (MIMO) channels in multi-mode fiber (MMF) links is investigated theoretically. Additionally, the performance of space-time block coding (STBC) techniques for achieving high reliability optical MIMO transmission is numerically examined. A comparative study is performed by considering several schemes that employ multiple transmitters/receivers. Simulation results of these schemes, in terms of bit error rate (BER) as a function of optical signal to noise ratio (OSNR), are provided.