## 2 MISO VLC System Model
According to the previous analysis, it is clear that the 16 arrays case has outperformed the two other cases, which encouraged the extension of this work to include 25 and 36 arrays. The analysis is repeated keeping a fixed number of LEDs for all array patterns and the same room parameters used in Table 1, except for the transmitter half power angle \(\varnothing_{1/2}\). The illuminance and received power investigations are repeated but this time employing an LED with \(\varnothing_{1/2}\) equal to 30\({}^{\circ}\), like the one used in Reference [14]. The obtained values are summarized in Table 7, where the 16 arrays case has the lowest illuminance level and the least illuminance STD. All the transmitter configurations under the condition \(\varnothing_{1/2}=30^{\circ}\) have an average illuminance within the illumination requirements of a typical room, but with the 16 arrays configuration having the advantage of better pattern uniformity. The calculations to obtain \(P_{r}\) are repeated for \(\varnothing_{1/2}=30^{\circ}\), the values are given in Table 8.  
Moreover, Table 9 includes the minimum BER values when the bit rate is varied to check the consistency of the conclusions attained. The variations between the five configurations at the same \(\varnothing_{1/2}\) are minimal, causing the 16 arrays to be the most efficient one even if configurations have slightly less BERs. Looking at Table 9, the five transmitter configurations showed an improvement in the BER performance at \(\varnothing_{1/2}=30^{\circ}\), for all data rates, over the case of \(\varnothing_{1/2}=70^{\circ}\). As depicted in Tables 7-9, the 25 arrays case has a higher \(P_{r}\) STD of 2.0, a slightly higher \(P_{r}\) average, and less BER when compared to the 16 arrays case. The STD of the SNR in this case is equal to 4.0, as opposed to 2.3 in the case of the 16 arrays. On the other hand, the case of 36 arrays has a \(P_{r}\) STD of 1.8, still higher than the case of the 16 arrays, resulting in a SNR STD of 3.7. It also has a slightly \begin{table}
\begin{tabular}{c c c c c c} \hline
**Illuminance (lux)** & **4 Arrays** & **9 Arrays** & **16 Arrays** & **25 Arrays** & **36 Arrays** \\ \hline Average & 407 & 373 & 326 & 355 & 350 \\ Minimum & 109 & 49 & 116 & 71 & 77 \\ Maximum & 654 & 730 & 440 & 604 & 575 \\ STD & 135 & 197 & 84 & 355 & 350 \\ \hline \end{tabular}
\end{table} 
Table 7: Illuminance at \(\varnothing_{1/2}=30^{\circ}\). higher average \(P_{r}\) when compared to the 16 arrays case, and less BER. However, these cases might not be practically preferred, as they will increase the complexity of the LEDs installation in the room. To summarize the outputs of this section, the 16 arrays configuration has persistently shown a better pattern uniformity in comparison with the other rectangular transmitter arrangements at \(\varnothing_{1/2}=30^{\circ}\), having;  
* The least \(P_{r}\) STD of 1.2
* The least SNR STD of 2.3
* The highest minimum illuminance of 116 lux
* The highest minimum \(P_{r}\) of \(-1.0\) dBm  
However, this comes at the expense of a slightly higher BER when compared to the other configurations. Hence, the 16 array configuration at \(\varnothing_{1/2}=30^{\circ}\) is chosen, and the preceding section is dedicated to the equalization of the LED fixtures.