[MUSIC] Hello, in this video we will introduce the concepts of Beamforming and discuss the beamforming architecture. In particular, we will discuss the three types of beamforming architecture. Namely, Analog Beamforming, Digital Beamforming, and Hybrid Beamforming. Lastly, we will summarize this video. Beamforming is a management of radio frequency (RF) waves wherein a wireless signal is directed towards a specific receiving device. It is the application of multiple radiating elements transmitting the same signal at an identical wavelength and phase. The signal strength of the radiation pattern (referred to as 'beam') in direction to UEs are much stronger than the other parts. Therefore, beamforming, increases the signal to noise ratio (SNR) at the UEs and, consequently, improves the data rate. In practice, there are three popular types of Beamforming. The first type is Analog Beamforming, wherein we control the phase and amplitude of the signal. In the figure you can see that the signal S(t) is transmitted from eight different antenna with different amplitude and phase values. Here, W1, W2, and W8 are the gain controllers. Theta 1, Theta 2, and Theta 8 are the phase controllers that generates the signal S1(t), S2(t), and S8(t) by making a suitable choice of the gain and phase values, we can generate a beam directed towards a particular user. Mathematically, it can be expressed as the sum of all the eight copies of S(t), that is s1(t), s2(t), and s8(t), where s1(t) can be expressed as |(w1e- jdTheta1 s(t). Similarly, s2(t) can be expressed as w2e- jdTheta2 s(t) and so on. Here, d is the distance between two antenna elements. Such an analog architecture helps us to generate a beam directed towards a particular user, but it can generate only single beam. The question is, what should we do to generate multiple beams so that we can support multiple users? For that multiple such structures are used as shown in the figure. The benefit of using analog architecture is that it does not require too many analog to digital converters, filters, etc. Because the phases are modified in the analog domain or the passband domain. Thus, it consumes less power, gives high gain, provides rapid and a reliable signal strength to the user equipment (UE). The second type is the Digital Beamforming, where we digitally control the phase and amplitude of the signal or linearly combining them. It provides a programmable and an adaptive control of the radiation pattern of antennas and beams to improve the signal to interference plus noise ratio (SINR) at the UEs. Although, the digital beamforming is an ideal choice, it is prohibited for large number of antennas because it requires a dedicated RF chain for each and every element of the antenna array, therefore, it is not used in massive MIMO system. Also, its complexity is high and consumes more power. The third and the last type is the Hybrid Beamforming, which combines the analog and digital beamforming together. In the diagram here, you can see that the K_t data streams are first digitally precoded and passed through the K_t number of RF chains and then, an analog beamforming architecture is used where different analog phase shifters and adders are used to transmit the signals through N_t number of transmit antennas. These large number of antennas are used to form highly directional beams, which help in improving the SNR and avoiding the interference that results in an enhanced throughput experience. In this video, we have learned the concepts of beamforming, followed by three popular beamforming architectures. Namely, analog beamforming architecture, digital beamforming architecture, and hybrid beamforming architecture. Thank you. [MUSIC]