Analytical performance evaluation of the OFDM systems passing through nonlinear circuits

Abstract

This paper presents a new and exact theoretical analysis of performance degradation of OFDM systems due to circuit nonlinearity effects. This nonlinearity is modeled as a fifth order memoryless nonlinear polynomial model. Theoretical analysis shows that the detected data symbol at the receiver consists of attenuated version of the original transmitted data symbol, third and fifth order intermodulation components. Analytical expressions for inter-modulation noise term are derived using combinatorial methods. By use of the derived expressions, a closed form output signal to noise ratio and degradation factor can be evaluated theoretically. The analytical results are compared with simulations outcomes.

Statistical modelling of a non‐linear high‐power amplifier with memory in multi‐input–multi‐output orthogonal frequency division multiplexing systems

“…Memoryless non-linearity in MIMO-OFDM systems is studied in [1,2] and non-linear MIMO-OFDM systems with memory are analysed in [3,4]. In addition, [5][6][7][8][9][10] examined OFDM systems with memoryless non-linearity and [11][12][13] considered memory effects. The analysis of non-linear effects in MIMO systems is limited and memoryless models are used frequently [14][15][16].…”

“…Various HPA models are considered in [17][18][19][20]. It is shown that a HPA with memory in OFDM and MIMO-OFDM systems can be modelled by an attenuation coefficient and an additive Gaussian noise in each subcarrier [4][5][6][7][8][9][10][11][12]. Analytical model and formulas of the attenuation coefficient and variance of additive Gaussian noise in MIMO-OFDM system are presented in [4].…”