In a communication system, the transmitter and the receiver are important. The function of the receiver is to recover the data being transmitted. Thus, the concentration is more on the receiver side. In this paper, the system performance of 2D ZCC/MD code has been evaluated in terms of received power, number of users and data rate using APD and PIN as photodetectors to suppress MAI and mitigate PIIN. The results demonstrate that the APD provides a preferable performance compared to PIN. The evaluation of the proposed code is done for the same code length of spectral encoding sequence and the same code length of the spatial spreading sequence (M = 21, N = 3) with the APD gain variation (1, 3 and 5) compared to PIN. The APD with G = 3 can accommodate 390 active users whereas, PIN can accommodate 322 active users at a lower bit rate and lower effective power (- 23dBm). The APD photo-detector is a feasible solution for a system to be used to provide excessive cardinality with a low bit rate in 2D ZCC/MD OCDMA system.
