Experimental analysis of multicore crosstalk impact on MIMO LTE-a radio-over-fibre optical systems

The impact of optical crosstalk in multicore fibres considering both internal and external optical interference on a MIMO radio-over-fibre optical transmission system is experimentally evaluated in this paper. The crosstalk impact is analysed on full-standard 3GPP LTE-Advanced (LTE-A) signals in both SISO and MIMO configurations for comparison. The experimental results indicate that LTE-A MIMO processing support high-levels of crosstalk induced by internal interference. In addition, LTE-A 2×2 MIMO signals using high modulation formats (64QAM) tolerate 5 dB more crosstalk induced by external interference than corresponding SISO configuration. The performance of the LTE-A signals in a 4-core multicore fibre is analysed experimentally in terms of launched optical power, time and wavelength performance. Finally, an optimum core-interleaving configuration is proposed and experimentally demonstrated comprising the specific transmission of LTE-A signals on spatial optical paths in opposite cores for the multicore fibre considered.