Nonlinear models of TWT revisited for OFDM systems

Author

Barbieri, A. ; Cariolaro, G. ; Vangelista, L.

Author_Institution

Dept. of Electr. Eng., Padova Univ., Italy

Volume

1

fYear

1995

Firstpage

522

Abstract

Recently, OFDM systems have received wide interest, particularly in the field of terrestrial broadcasting of all digital television in the UHF/VHF bands. The use of TWT (Traveling Wave Tubes) is considered for the final amplification of the OFDM signal. The OFDM modulated signal is very close to a Gaussian random process. In this paper we revisit the most popular TWT models and recognize that they belong to a peculiar class of non-linearities, S×FSM, in which the output is the product of the incoming complex signal and a function of its modulus. For S×FSM nonlinearities, driven by a Gaussian input, output statistics can be evaluated in closed forms. We apply this analysis to the TWT non-linearity, deriving the power spectral density of the output signal as well as the probability density function, when the input is an OFDM signal

Keywords

Gaussian distribution; Gaussian processes; frequency division multiplexing; spectral analysis; travelling wave tubes; Gaussian input; Gaussian random process; OFDM modulated signal; OFDM systems; S×FSM nonlinearities; TWT; UHF band; VHF band; all digital television; closed form output statistics; nonlinear models; orthogonal frequency division multiplexing; power spectral density; probability density function; spectral analysis; terrestrial broadcasting; traveling wave tubes; Digital TV; Gaussian processes; Linearity; OFDM modulation; Probability density function; Random processes; Signal analysis; Signal processing; Solid modeling; Statistical analysis; Statistics; TV broadcasting;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 1995., Proceedings., Proceedings of the 38th Midwest Symposium on

Print_ISBN

0-7803-2972-4

Type

conf

DOI

10.1109/MWSCAS.1995.504491

Filename

504491