# Recording a Hologram Transmitted over a Communication Channel on One Sideband
## 1 Introduction
The second is a map of the 3D surface onto which the texture is superimposed, thus forming an image of the 3D object, or a mask of the object. Thus, extremely large amounts of information contained in holograms and preventing transmission along conventional communication channels may be compressed without any damage to the acceptable size, comparable with a generally accepted television frame of the Full HD or 4K standard. In this case, transmission of holographic information (Figure 1) resembles the single sideband modulation (SSB) known in radio engineering, because the carrier spatial frequency responsible for the spatial separation of the zero and minus first diffraction order carrying the information on the 3D holographic object is absent in this case. The holograms of the single sideband of spatial frequencies, transmitted along the channel, were synthesized by returning the carrying spatial frequency. It is rather difficult to reproduce these holograms using the classical method of repeating holographicing technology according to the scheme proposed by [PERSON] and [PERSON]. This can be implemented in a much easier manner using the technology based o  
Figure 1: The transmitted information on a 3D object: (**a**) texture, (**b**) mask, (**c**) 3D assembly. scheme. The first hologram transmitted along a conventional communication channel in real time was recorded using this technology. The parallax of the image restored by this hologram was measured. The outlooks for the use of these holograms are discussed. The direct SSB transmission was performed along the Wi-Fi channel in the packages containing 500 pairs of images, as in those shown in Figure 1a,b, with the measurement of transmission rate [17]. An experimental transmission of the sequence of signal pairs of this kind (Figure 1a,b) was carried out over a wireless Wi-Fi channel to imitate a 3D video. For this purpose, a File Transfer Protocol (FTP) was installed at the transmitting device, while the FileZilla software for working with FTP servers was installed at the receiving device. Each transmitted frame of a 3D image was the sum of two 2D frames: a texture (2000 \(\times\) 2000 pixels) and a mask (1000 \(\times\) 1000 pixels). To imitate the transmission of a video sequence, the packages of 500 double frames was transmitted simultaneously. The time of the frame package transmission measured using FileZilla software during reproduction in real time was 12 s for the frames formed in the JPEG file format, and 51 s for the frames formed in the PNG format, which is equivalent to transmitting 41.67 and 9.8 double frames per second, respectively. This means that, at least for the JPEG format, the actual rate of 3D signal transmission within a narrow bandwidth of the Wi-Fi channel (IEEE 802.11n standard) was sufficient to provide the TV frame rate standard. On this basis, it may be concluded that the transmission of a full image of a 3D object in real time, with a frame rate higher than 25 frames per second, is quite accomplishable with this device configuration. The hologram is synthesized at the receiving end of communication channel with the help of the digital method using the transmitted information on the 3D holographic object. This hologram is a material analog of a holographic display [14] reconstructing the image of this object. This hologram may be of any type; however, virtual synthesis of the most widespread holographic displays, according to the scheme proposed by [PERSON] [18], is hindered during the transformation of a virtual hologram into its material analog. Because of this, in our first paper presented at the HoloExpo 2021 conference _Features of the synthesis of SSB holograms_ (SSBH) [19], we chose the synthesis of holograms at the receiving end of the communication channel, according to the scheme proposed by [PERSON] and [PERSON]. However, the work with this type of hologram involves several problems that are difficult to solve.