Orthogonal Modes using Prolate Spheroidal Wave Function in Holographic Communication Systems

Beyond 5G (B5G) communication systems refer to the sixth generation (6G) of mobile communication which is expected to offer speeds up to 100 times faster than the current 5G communication systems. In addition, 6G communication systems are expected to use more advanced spectrum such as Terahertz (THz) or millimeter Wave (mmWave) communication, allowing for much higher data rates. Holographic communication involving Large Intelligent surfaces (LIS) is an optimal and efficient way of communication for 6G or B5G. It ensures effective and precise communication of data from transmitter to receiver. It is considered to be the ultimate form of wireless communication, using large antennas operating at THz frequencies in the Fresnel region (radiating near-field). In this paper, the region or boundary for large size antenna surfaces are explored. In comparison to traditional MIMO (Multiple Input Multiple Output) systems, it is possible to exploit Degrees of Freedom (DoF) values greater than 1 even in strong Line of Sight (LoS) channel conditions, resulting in a notable increase in spatial capacity, particularly when operating at THz or mmWaves range. The Prolate Spheroidal Wave Function (PSWF) and Ultra-Wideband (UWB) Pulse Shapes are used to generate Orthogonal Modes. The time-limited and broad bandwidth characteristics of the orthogonal signal waveforms make the PSWF a great asset in the design of UWB pulse-shapes. The use of Legendre polynomials yields modes that are mutually Orthogonal. By utilizing Holographic communication systems, the capacity of a channel can be enhanced when compared to classical communication systems.