Analytical performance evaluation of the OFDM systems in the presence of jointly fifth order nonlinearity and phase noise

Abstract

This paper presents an exact theoretical analysis of the performance degradation in an orthogonal frequency division multiplexing (OFDM) system when the signal including phase noise is passed through a nonlinear circuit such as high power amplifier (HPA). This circuit is modeled as a fifth order memory-less nonlinear polynomial model (5th order MLNPM). The nonlinear model is derived from important electrical parameters such as gain, 1-dB compression and 3rd order intercept point. Theoretical analysis shows that the detected data symbol at the receiver consists of attenuated version of the original transmitted data symbol, common phase error (CPE), intersub-carrier interference (ICI), third and fifth order intermodulation (IM) components. The analytical expressions for intermodulation noise term are derived using combinatorial methods. By use of the derived expressions, a closed-form output signal to noise ratio (SNR), degradation factor (DF) and probability of error can be evaluated theoretically. For verifying the accuracy of our analysis, comparisons between the theoretical and simulated results with electrical parameter of an actual and applicable HPA are presented. The comparisons show that bit error rate (BER) of analytical results is closely match with simulation results for OFDM system using M-QAM modulation.

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].…”

“…GMP complexity is less than Volterra model [21] and higher than memory polynomial (MP) model, but its performance is comparable to Volterra and it has the attractive property of MP [22,23] which is analytical tractability. The MP model is widely used in the behavioural modelling of HPA [11][12][13].…”

New single-parameter models for nonlinear electronic systems and its use in predicting intermodulation performance

“…In [15][16][17] Taylor series was used to model the inputoutput characteristic of a nonlinear electronic system. Using these Taylor series and the procedures described in [24][25][26] it is easy, though mathematically cumbersome, to calculate the amplitudes of the output intermodulation products resulting from a multisinusoidal input.…”