# A Critical Examination of the Beam-Squinting Effect in Broadband Mobile Communication: Review Paper
## 3 Studies Related to the Beam Squint Effects
The goal of beamforming was to choose the best weight vectors for the transmitter and reception antennas with high antenna gains or the best beam pattern pairings, and this criterion depended on several factors, including capacity, the signal-to-noise and interference ratio (SNIR), and others. It was found that the phenomena of beam squint are caused by distinct frequency bands away from the 60 GHz core frequency. The authors established three different codebook strategies in order to cut down on beam squint. The initial methodology is referred to as the \"Phase Improvement Scheme Based on 3C Codebook.\" The authors of this plan developed codebooks for a number of different bands and altered the phase by utilising an additional phase shifter. The suppression of the beam squint resulted in a reduction in the amount of spatial interference and an increase in system capacity. On the other hand, the enhanced system capacity came at the expense of an increase in the complexity of the implementation. A comparison of the most common approaches of removing the squint effect from beams is shown in Table 1. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Parameter** & **Digital Beamforming** & **Analog Beamforming** & **Codebook Design** \\ \hline \multirow{3}{*}{Complexity} & \multirow{3}{*}{High complexity} & \multirow{3}{*}{Acceptable complexity} & \multirow{3}{*}{Increases the number of phase shifters, which increases the complexity} \\  & & & & \\ \cline{1-1}  & & & & \\ \hline \multirow{3}{*}{Cost} & Increased hardware requirements lead to a high cost & Compared with their digital counterparts, the costs are much lower & Power and cost rose significantly \\ \hline \multirow{3}{*}{Effectiveness} & Incredibly efficient at correcting the squint & Has the potential to decrease the effect of squinting and improve efficiency & Able to significantly lessen the \"squint\" effect \\ \cline{1-1}  & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison among the main methods used to remove beam squint effect. Figure 9: Series-fed active antenna array [47]. The authors proposed the \"MRA Alignment Scheme Based on Uniform-Weighting Codebook\" as the second scheme to enhance system performance. The final proposal assumed that since neighboring parts have a strong correlation, it was possible to alter the phase of two nearby antennas using a single-phase shifter, which significantly reduced the complexity of the transceiver. Figure 10 shows compression among the three schemes as a function of the system capacity. Although these schemes worked very effectively in removing the beam squint, they increased the system complexity by increasing the number of phase shifters. In [50], the beam squint problem in Uniform Linear Array (ULA) was modelled, and its effect on codebook design was analyzed. The study demonstrated that beam squint reduces the bandwidth that is usable. The authors created an algorithm to fix codebook designs with beam squint. The goal of codebook design was to ensure that every beam exceeds a specified threshold and has a minimal gain for a variety of frequencies and angles in the wideband system. Analysis and numerical examples indicated that to account for beam squint, a denser codebook was needed. In other words, compared with a codebook design that disregards beam squint, more beams were required. In order to boost the expected average beam gain, the authors of [51] studied the beam squint issue in mmwave communication and suggested a beamforming architecture that optimizes average beam gain inside the bandwidth while minimizing average beam gain outside the bandwidth. Additionally, the design shows little variation in the bandwidth at various frequencies. To take into account the beam squint and guarantee constant beam gain for each subcarrier in the wideband system, the authors suggested a beamforming approach based on space-time block coding.