Agrawal, Anand2019-10-042023-10-202019-10-042023-10-202018ROLL NO.126102011https://gyan.iitg.ac.in/handle/123456789/1377Supervisors: Rakhesh Singh Kshetrimayum and A RajeshTo be able to connect wirelessly to the internet is nowadays a basic part of daily activity and the number of wireless devices accessing wireless networks are increasing rapidly. However, the significant growth in the number of wireless devices along with the development of new high-rate applications and scarcity of microwave frequency spectrum are the major challenges. A promising way to increase the amount of available bandwidth is to utilize the higher frequency spectrum. Ultra- wideband (UWB) and Millimeter wave (mm-Wave) are the potential technologies for high-rate and short distance wireless communication. Both technologies have received great attention due to the license-free utilization of wide available frequency spectrum. Apart from the benefits, wide frequency spectrum has introduced few additional challenges in the typical Saleh-Valenzuela (S-V) channel model. One of the challenges in the modified S-V channel model is the distribution of multipath gain coefficients are lognormal rather than Rayleigh. As we know that, a lognormal random variable has no closed-form expressions of its cumulative distribution function, moment generating function and characteristic function, which are required to find the closed-form BER expression of wireless systems for such channels. For this reason, a lot of research has to be conducted to find the computable BER formulae for such wireless communication systems. Therefore, the thesis focuses on the derivation of computable BER formulae of UWB and mm-Wave wireless communication systems. Firstly, we present an approximate model of a square of lognormal shadowing by a Mixture of Gamma (MG) distributions by using a moment-matching with non-linear curve fitting method.enELECTRONICS AND ELECTRICAL ENGINEERINGThesis