Performance evaluation of PIN+OA and APD receivers in multi-wavelength CDMA and WaCDMA networks

Abstract

In this paper, the performance of multi-wavelength optical orthogonal code division multiple access (MWOCDMA) communication network and hybrid wavelength code division multiple access (WaCDMA) network are investigated. In both the networks, transmitted signal is coupled into a dispersion shifted fiber (DSF) which in turn is coupled to either a PIN+OA or an APD receiver. The expression for probability of error for the above receiver configurations in MWOCDMA and WaCDMA networks are derived taking into consideration various sources of receiver noise, multiple user interference and four wave mixing (FWM) effects. It is observed that for a given number of users, MWOCDMA networks with PIN+OA receiver and WaCDMA networks with APD receiver are preferred to achieve a required performance. Further, the former give improved performance as compared to the latter with the level of improvement depending upon the number of users for which the network is to be designed. This is valid for all values of link loss. However, at higher values of link loss, FWM effect becomes dominant since the transmitted power is high and it leads to a smaller range of input transmitted power levels for a given number of users and performance requirement.