BER performance of OFDM signals in presence of nonlinear distortion due to SSPA
Orthogonal frequency division multiplexed signals typically exhibit large dynamic ranges due to superposition of a large number of subcarrier signals. As a result, such signals are highly vulnerable to distortion caused by high power amplifier (HPA) nonlinearity, leading to degradation in bit error rate (BER). In turn, the HPA operating point should be backed off to compensate for such degradation at the expense of the HPA efficiency. In this paper, the considered amplifier chain is a solid state power amplifier of Rapp's model. We develop the factors contributing to BER degradation in terms of the input backoff (IBO) level assuming quadrature phase shift keying modulation. Consequently, the BER performance for such an amplifier model is developed as a function in IBO. Then, we show how this developed performance can be used to determine the required HPA operating point to achieve a certain required BER. Accordingly, an improvement in the amplifier efficiency is achieved. All developed analytic expressions are compared against simulationmeasurements, which show that good agreement exists.
|Keywords||Nonlinear distortion, Orthogonal frequency division multiplexing (OFDM), Solid state power amplifier (SSPA)|
|Journal||Wireless Personal Communications|
Helaly, T. (Tarek), Dansereau, R, & El-Tanany, M. (2012). BER performance of OFDM signals in presence of nonlinear distortion due to SSPA. Wireless Personal Communications, 64(4), 749–760. doi:10.1007/s11277-010-0217-z