Indoor hybrid fibre and wireless CDMA system using optically preamplified fibre coupled receiver

Hybrid fibre and optical wireless systems are a potential route to flexible access networks. When combined with code division multiple access (CDMA), there is the possibility of using a power combiner to extend the network to multiple users in a wider coverage area or different rooms and such a scheme is proposed and analyzed here. Moment generating function (MGF) techniques are used to account for the amplified spontaneous emission noise (ASE) resulting from optical amplification and bit error rate (BER) analysis is performed using the Saddle point approximation (SPA), Chernoff bound (CB) and the Gaussian approximation (GA). Different codes and splitting ratios are used to analyze the hybrid fibre and wireless systems from ceiling unit to ultimate receiver, exemplifying the cases where number of users is restricted by code or split.