Optical MIMO multimode fiber links channel measurements and system performance analysis

Wireless communication is nowadays one of the areas attracting a lot of research activity due to the strongly increasing demand in high-data rate transmission systems. The use of multiple antennas at both the transmitter and receiver side has stimulated one of the most important technical breakthroughs in recent communications allowing increasing the capacity and dropping the bit-error rate. However, multiple-input multiple-output (MIMO) systems are not limited to wireless MIMO systems and can be observed in a huge variety of transmission links and network parts and have attracted a lot of attention since the mid 90's. In the field of optical MIMO transmission systems, multi-mode (MM) fibre offers the possibility to transmit different signals by different mode groups. The perspective of the MIMO philosophy within the field of optical transmission systems is elaborated in this contribution based on channel measurements within a (2 × 2) MIMO system. For the channel measurements the second optical window and a fibre length of 1.4 km was chosen. Computer simulations on an overall data rate of 10.24 Gbps underline the potential of multi-mode fibres in optical high-data rate MIMO communication systems and show that in order to achieve the best bit-error rate, not necessarily all MIMO layers have to be activated.