Abstract For achieving high-capacity in optical communication systems, multiple wavelengths are transmitted over a single fiber; this system is called Dense Wavelength Division Multiplexing (DWDM). However, system performance is significantly affected by the transmission link distance, the gain of the used amplifier, the receiver sensitivity, and the channel spacing. In this paper, a comparative analysis of direct-detection and coherent-detection receivers is performed for an eight-channel DWDM system, where each channel operates at 10 Gb/s. The performance of both receiver architectures is simulated in terms of bit error rate (BER) and Q-factor for different transmission parameters. Simulation results demonstrate that the system’s performance degrades with increasing link length due to attenuation, dispersion, and amplified spontaneous emission noise. The coherent detection receiver exhibits improved sensitivity and greater tolerance to varying channel impairments compared with direct detection. Furthermore, optimal EDFA gain and channel spacing values are identified to achieve an acceptable BER for the two receivers. The proposed study provides a detailed analysis of comparing the performance of two receiver architectures in DWDM systems and offers insights for optimizing high-capacity optical networks.
Pushparajesh et al. (Mon,) studied this question.