## 2 Wireless B5G Difficulties with DL-Based Mm-Wave
### DL-Based Mm-Wave  
A recently emerging field of study called \"DL-based mm-wave\" looks at applying DL methods to enhance mm-wave communication systemure performance. Signal processing and RA have special challenges because of the high frequency of mm-wave signals and the directed character of the antenna arrays utilized in mm-wave systems. DL can facilitate RA and intelligent, adaptive signal processing, which can assist in overcoming these issues [36]. For mm-wave communication, DL is applicable for channel modeling with the application of DL so that channel models that consider the intricate relationships between the environment, the antenna array, and signal propagation may be created with accuracy and efficiency. These channel models can be utilized to enhance system performance, create more effective RA rules, and optimize the beamforming procedure [40]. By understanding the intricate correlations between the antenna array configuration, channel situations, and performance metrics like throughput, latency, and EE, DL can be used to optimize the beamforming process [37, 38, 39]. For RA in mm-wave systems, DL can be applied to optimize the distribution of resources, including time, power, and frequency. The system's performance may be enhanced by increasing network capacity, enhancing reliability, and lowering power consumption [10]. The performance, reliability, and efficiency of wireless communication networks might all be greatly increased by the application of DL in mm-wave communication. However, a thorough evaluation of the system requirements, channel conditions, and available computational resources is necessary to design and optimize DL for mm-wave communication [13, 41]. DL is emerging as a key enabler of mm-wave technology, which operates between 30 and 300 GHz and offers significantly higher bandwidth for B5G networks, improving capacity, speed, and reliability. However, optimizing mm-wave technology requires addressing challenges in processing power, channel conditions, and system requirements. All of this was achieved while using very little power (less than 1 watt) to transmit at 73 GHz [62, 63, 64, 65, 66] as shown in Table 1. The potential of DL and beamforming training to enable dual optimization of EE and SE in the face of the difficulties of mm-wave communications makes them crucial for wireless B5G systems. B5G systems may effectively lower the RF chain, reduce channel-estimate complexity, and improve both EE and SE by combining DL with beamforming training. This opens the door to more dependable and effective communication. Table 2 lists several issues with wireless communication, including transmission delays, the increasing demand for smaller devices, caching optimization, and restricted capacity, particularly for applications like UAVs and D2D communication. mm-wave technologies, which provide greater bandwidth, reduced latency, and the potential for smaller antennas, are used to overcome these problems. \begin{table}
\begin{tabular}{c c c c} \hline
**Ref.** & **Frequency (GHz)** & **Scenario** & **Application** \\ \hline
[63] & 60, 70 & Indoor & Mix-Media \\
[64] & 60 & Wireless LAN & Access to uplink channels \\
[65] & 28, 38, 71, 81, 86 & Urban areas & Access and backhaul \\
[66] & 30–60 & Wireless PAN & Transmission of video in ultra-high definition \\
[67] & 60 & Wireless PAN & Quick device-to-device data transfer \\ \hline \end{tabular}
\end{table} 
Table 1: mm-wave scenarios applications. In this article, we provide the key aspects of mm-wave technology for wireless communication. * The properties of mm-wave signals, which have a short wavelength and high attenuation, limit their range and ability to penetrate obstacles. However, these properties can be harnessed for directional communication, enabling beamforming and beamsteering techniques that can enhance the signal quality and reduce interference. * The potential applications of mm-wave technology, including high-speed data transmission, remote sensing, and vehicular communication.