Performance comparison of LSMS and conventional diffuse and hybrid optical wireless techniques in a real indoor environment

Performance evaluations were carried out for indoor optical wireless systems in three different environments. Channel characteristics of infrared links have been evaluated under various conditions including an empty room, a room with glass windows and a door, and a room that has very strong shadowing effects caused by mini cubical offices. The corresponding results have been analysed and compared for conventional diffuse/hybrid systems (CDS/CHS) and line strip multibeam transmitter systems (LSMS) that use spot diffusing techniques. Eight directive lamps represented the ambient light noise and allowed further signal impairments to be taken into account. Under these conditions, results indicate that LSMS can reduce pulse spread by factors of 11 and 24 compared to the maximum delay spread associated with CDS and CHS respectively. Furthermore, LSMS links can increase the SNR by more than 50 dB compared to the CDS and CHS.