Performance analysis of differential quadrature phase shift keying modulation schemes for a radio over fiber system

Abstract

Radio over fiber systems have become one of the best options for backhaul due to their larger bandwidth, low propagation loss, and competitive cost. Advanced modulation formats play a key role in enhancing the performance of fiber optic communication systems by providing higher bit rates and less susceptibility to noise in long distance transmission. This paper presents a detailed analysis of differential quadrature phase shift keying modulation in a radio over fiber system at 60 GHz for 5G applications. The differential quadrature phase shift keying modulation is combined with two different advanced phase modulation formats, i.e., return-to-zero and carrier suppressed return-to-zero to provide higher spectral efficiency. The performance of the system has been investigated at 10 and 20 Gbps data rates for 10 to 50 km transmission lengths of different types of fiber. Overall, it has been observed that carrier suppressed return-to-zero differential quadrature phase shift keying is better as compared with return-to-zero differential quadrature phase shift keying at both 10 and 20 Gbps data rates up to a transmission length of 50 km.