On performance of cooperative network based on OFDM combined with TDM using MMSE-FDC in the presence of nonlinear HPA

• Published in: EURASIP journal on wireless communications and networking 2013-07, Vol.2013 (1), p.185-185, Article 185
• Main Authors: Ligata, Amir, Gacanin, Haris, Adachi, Fumiyuki
• Format: Article
• Language: English
• Subjects: Communications Engineering; Engineering; Information Systems Applications (incl.Internet); Networks; Signal,Image and Speech Processing
• ISSN: 1687-1499; 1687-1499
• DOI: 10.1186/1687-1499-2013-185

In this paper, we analyze the impact of nonlinear high-power amplifier (HPA) on the performance of cooperative network based on orthogonal frequency division multiplexing combined with time-division multiplexing (OFDM/TDM) using minimum mean-square-error frequency-domain combining (MMSE-FDC) in a frequency-selective fading channel. We design a novel MMSE-FDC weights while taking into account the nonlinearity of HPA at source and relay. Closed-form symbol error rate and outage probability expressions are derived while approximating the residual inter-slot interference after the MMSE-FDC as a random Gaussian variable. We discuss and address the nonlinear OFDM/TDM system design issues in cooperative network using the obtained simulation and theoretical results. We show that the OFDM/TDM with MMSE-FDC can be used to reduce the impact of nonlinear HPA on overall performance of cooperative network in comparison to OFDM while providing the target quality-of-service for reduced required signal-to-noise ratio. This is because OFDM/TDM with MMSE-FDC achieves frequency diversity in addition to cooperative diversity, while reduced peak-to-average power ratio makes it more robust on nonlinear degradation due to HPA saturation in comparison to conventional OFDM.