Evaluation of Clipped-OFDM and SC/FDE Alternatives for Block Transmission Using Iterative Receiver Techniques

A CP-assisted (cyclic prefix) block transmission is widely accepted as a good choice for future mobile systems, taking advantage of low-cost, flexible, FFT-based (fast Fourier transform) signal processing technology with both OFDM (orthogonal frequency division multiplexing) and SC (single carrier) alternatives. The OFDM alternative provides a simple receiver implementation which allows good performances, by exploiting the channel coding effort, but is known to suffer from a high PMEPR (peak-to-mean envelope power ratio), leading to power amplification difficulties. The SC/FDE (frequency-domain equalization) alternative is easily compatible with low PMEPR values, but the FDE (MMSE) receiver performance is known to be far from the optimum. In this paper, we consider a reduced-PMEPR, clipped-OFDM transmission , where an advanced receiver performs the iterative cancellation of the deliberate nonlinear distortion effects. In parallel, we consider an advanced turbo FDE receiver, as well as simplified iterative FDE receiver implementations, within the SC alternative. The "SC vs OFDM" comparisons of this paper, under the use of iterative receiver techniques in both cases, show a very significant overall advantage for the SC side.