Performance Analysis of CSRZ-DQPSK Modulator for RoF-PON-Based Wireless Access
Conventional schemes use three Mach–Zehnder modulators in the transmitter for the generation of CSRZ-DQPSK signal in passive optical networks. It also simultaneously provides wireline connectivity till ONU and wireless access from ONU, without the need of a separate RF source at the ONU. In this paper, a design of CSRZ-DQPSK transmitter with reduced complexity using two Mach–Zehnder modulators (MZM) and performance analysis of the wireless access from the ONU is analyzed. For wireless transmission of high data rate, a 20 GHz RF carrier signal is generated at the ONU from the received 20 Gbps CSRZ-DQPSK signal. Further, QAM modulation technique is used for 5 Gbps wireless data transmission from the recovered 20 GHz carrier signal. System simulation of the entire fiber link is carried out in Optisystem, and the performance of 2-MZM-based transmitter is analyzed for the wireless transmission from the ONU to the user end, using the eye diagram and received power. Results indicate that 2-MZM-scheme achieves similar performance compared to conventional 3-MZM scheme.
KeywordsMach–zehnder Modulator (MZM) Carrier-suppressed return-to-zero (CSRZ) Differential quadrature phase shift keying (DQPSK) Quadrature amplitude modulation (QAM) Radio over Fiber (RoF)
- 1.AI-Raweshidy H, Komaki S (2002) Radio over fiber technologies for mobile communication network. Artech House Publishers, NorwoodGoogle Scholar
- 2.Ji W, Chang J (2013) IEEE Trans Opt Commun Netw 5Google Scholar
- 3.Agarwal GP (2010) Fiber optic communication systems. Wiley, New YorkGoogle Scholar
- 4.Ho K-P (2005) Phase-modulated optical communication systems. Springer series in Optics and Laser, New YorkGoogle Scholar
- 5.Dong Y, He H, Su Y, Hu W (2006) RZ/CSRZ-DPSK signal generation using only one Mach-Zehnder modulator. In: Proceedings of the optical fiber communication conference, Mar 5, Anaheim, California United StatesGoogle Scholar