## 1 Introduction  
The most common approach to designing a wireless communication system is to design a wireless communication system (i.e., a wireless communication system), and to design a wireless communication system (i.e., a wireless communication system). The wireless communication system is a _single_-carrier (i.e., a wireless communication system), and the _single-carrier (i.e., a wireless communication system) is a _single-carrier (i.e., a wireless communication system). The _single-carrier (i.e., a wireless communication system) is a _single-carrier (i.e., a wireless communication system), and the _single-carrier (i.e., a wireless communication system) is a _single-carrier  
## 1 Introduction  
Orthogonal frequency division multiplexing (OFDM) is a widely used modulation technique in optical communication systems due to its high bandwidth efficiency, ability to mitigate narrowband interference and dispersion effects, and suitability for high data rate transmission. With a cyclic prefix, OFDM can combat both inter-carrier interference (ICI) and inter-symbol interference (ISI) [1]. When higher-order quadrature amplitude modulation (QAM) is used, it improves link efficiency by allowing for high data rates with a low bit error rate (BER) [2]. A radio-over-fiber (RoF) system is capable of overcoming the limitations caused by the impairments in the optical domain since it leverages the low-loss transmission properties of optical fiber to transmit the mm-wave signals over long distances with minimal signal degradation [3], and it has several benefits, including excellent spectral efficiency, fast signaling, and low functional expenses [4]. End-to-end communication in a mm-wave A-RoF system necessitates the integration of both wireless and optical domain advancements, which greatly increases the link distance [5] in joint optimization of the 5G fronthaul (FH) for end-to-end C-RAN architectures [6], achieving data rates up to 80 Gbit/s [7]. The V-band frequency range enables high bandwidth [8], high throughput, and cost-efficient solutions for delivering high data rate [9] communications in optical networks, which are made possible by converged mm-wave A-RoF systems. However, chromatic dispersion in the standard single-mode fiber (SSMF) is creating ISI, especially in high-bit-rate systems (\(\geq\)10 Gbit/s) using OFDM. While narrowband transmitters can solve dispersion-related issues for data rates up to 2.5 Gbit/s, chromatic dispersion limits the transmission distance in high-data-rate systems [10]. Therefore, it is necessary to prevent the deterioration of the output signal due to ISI, which could be achieved either in the optical domain or using equalization techniques in the electrical domain. The intensity-modulation and direct-detection (IM-DD) design with external modulators is the most commonly used technique for RoF transmissions [11,12]. In [13], authors demonstrate nonlinear post-equalizers, such as a Volterra series-based equalizer and a neural network-based (NN) equalizer, to combat signal degradation in a 28 GHz mm-wave A-RoF FH link with transmission over a 10 km fiber using an optical single-sideband modulation format. In 64-QAM, both equalizers achieve BER < 3.8 \(\times\) 10\({}^{-3}\); additionally, when the NN equalizer is used after OFDM 16-QAM along with least-squares equalization, it obtains better BER. The proposed solution in [14,15] describes an artificial neural network nonlinear equalizer (ANN-NLE) for single-carrier 16-QAM and 64-QAM signals in a 60 GHz RoF communication system. It validates the approach to ensure effectiveness in equalizing the signal and improving the transmission performance. Moreover, an experimental demonstration of the 60 GHz RoF system is conducted utilizing an adaptive activated ANN-NLE to enhance the BER performance and effectively transmit a 5 Gbit/s Binary Phase Shift Keying (BPSK) signal across a 10 km fiber while maintaining a forward error correction limit of 10\({}^{-3}\).