Performance evaluation of a pyramidal fly-eye diversity antenna in an indoor optical wireless multipath propagation environment under very directive noise sources

An investigation into the optical wireless system performance has been carried out for both a conventional hybrid system (CHS) with a single detector under various receiver fields-of-view (FOV) and a pyramidal fly-eye diversity receiver (PFDR) with different FOVs. The effects of background noise produced by artificial ambient light sources and multipath dispersion have been considered. Original results for a hybrid system that employs a PFDR antenna, under different FOVs, are presented. It is found that the proposed PFDR can achieve a probability of error of 10^-9 when an optical wireless system operates in a room illuminated by spotlight sources with a directive beam. It is also demonstrated, through FOV optimisation of both the CHS and the PFDR, that the CHS performance is more severely affected by background noise and multipath dispersion than a PFDR system. Furthermore, SNR results are presented demonstrating that the optimised PFDR antenna gives about 4 dB improvement over the conventional hybrid systems. It is also demonstrated that the pulse spread induced by the multipath dispersion is significantly reduced when the PFDR receiver FOV is set to its optimum value.