Best Paper Award 2014

Best Paper Award

Nonlinear Modeling and Analysis on Concurrent Amplification of Dual-Band Gaussian Signals

Ikuma Ando, Gia Khanh Tran, Kiyomichi Araki, Takayuki Yamada, Takana Kaho,
Yo Yamaguchi, Kazuhiro Uehara

[Trans. Electron., Vol. E96-C No.10, Oct. 2013]

Ikuma Ando	Gia Khanh Tran	Kiyomichi Araki	Takayuki Yamada
Takana Kaho	Yo Yamaguchi	Kazuhiro Uehara

  In this paper, a wideband power amplifier (PA) and nonlinear compensation technique on concurrent amplification of multiband signals were examined, as a core technology of User-Centric Wireless Networks - the integration of various wireless systems on a unified hardware platform facilitating users’ flexible network connections. Concurrently amplifying the multiband signal of high power exceeding the linear region of the PA will result in not only intermodulation distortion but also harmonic distortion. Conventional studies on compensation techniques have only dealt with intermodulation but harmonic distortion since they only considered two-tone carriers of near frequencies.
  As a study of the distortion compensation technique for the case of a more severe condition when inputs are in a harmonic relationship, this paper propose a nonlinear distortion modeling method of combining the Volterra series expansion and generalized Wiener model, which enables the modeling of the complicated nonlinear distortion when concurrently amplifying multiband signals. Using this model and exploiting the Gaussianity of OFDM inputs, the paper can also derive, in closed form, various PA output quantities including the power spectral density, adjacent channel leakage power ratio (ACLR) and error vector magnitude (EVM). In a simple way, the paper has established a practical framework for investigating the amplifier characteristics on concurrent amplification of multiband signals.
  In summary, this paper presents a thorough investigation, in both theoretical and experimental manners, of the nonlinear characteristics and the compensation technique on concurrent amplification of multiband signals. For these reasons, the paper is a suitable candidate for the Best Paper Award.