In a multichannel transmission system, such as wavelength division multiplexing (WDM) with constant transmit power, the maximum achievable SE is an increasing function of the channel quantity and OSNR. To achieve high spectral efficiency (SE), which mainly represents the maximum theoretical data throughput of a system and how efficiently the total available bandwidth is being used, high order modulation formats can be used according to the available optical signal-to-noise ratio (OSNR). Optical fiber is utilized in FOCS applications in two basic forms, from short range which use multi mode fiber (MMF) to long-haul links employing single mode fiber (SMF). The ultimate goal of a FOCS is to provide high throughput through the desired transmission range, which requires careful design considerations for the system configuration, generally consists of a transmitter (Tx), optical fiber as the channel, and a receiver (Rx).
The optical amplification enabled increase in repeater spacing and wavelength division multiplexing (WDM), which resulted in ultrahigh bit rates and making the FOCSs a primary mean of information transportation on a global scale.
The advancement of fiber optic communication system (FOCS) is spread over various generations, which was boosted by the advent of Erbium-doped fiber amplifier (EDFA) in the 1980s because it enabled long-haul transmission. The increased demand for bandwidth and low-cost transmission over long distances led to the use of the optical waves by 1970s, to achieve ultralarge capacity and use optical fiber as the transmission medium. The introduction of telegraphy in 1830s led to the development and design of many further telecommunication technologies.
The simulations are performed considering Dual Polarization- (DP-) QPSK modulation format to achieve two-fold data rate to achieve spectral efficiency of 3.28 bits/s/Hz by making use of the polarization diversity and system performance is investigated in terms of bit error rate (BER), constellation diagrams, and quality factor (Q-factor) for different values of optical signal-to-noise ratio (OSNR), launch power ( ), and fiber length. In this paper, digital signal processing- (DSP-) assisted dispersion and nonlinear compensation techniques are presented to compensate for physical layer impairments including OFCD, PMD, and POaN.
The development of components and algorithms to minimize these effects in next generation FOCSs with 100 Gbps data rate and beyond with long-haul transmission is still a challenging issue. Thus, the effects that add up to the optical fiber impairments such as optical fiber chromatic dispersion (OFCD), polarization model dispersion (PMD), and phase offset and noise (POaN) need to be addressed at the receiver side. Advanced modulation formats make use of the phase, amplitude, and polarization of the optical signals at the same time to provide high spectral efficiency as compared with 1 bit/s/Hz for the intensity modulation direct detection system (IMDD), but are highly prone to transmission impairments. Fiber optic communication systems (FOCSs) have attained a lot of attention by revolutionizing the telecommunication industry and offering new possibilities with the technical advancements in state-of-the-art high speed digital electronics.