Peak reduction for OFDM by shaping the clipping noise

The high peaks of an orthogonal frequency division multiplexing (OFDM) signal are distorted nonlinearly by the high power amplifier (HPA). Clipping techniques can reduce the peaks. Most conventional clipping techniques consider the inter carrier interference (ICI) due to clipping noise to be white and Gaussian distributed. In conclusion it is tried to minimize the interference power. In contrast to that alternative noise distributions are investigated in this paper. A transmitter design based on the active constellation extension (ACE) technique (B.S. Krongold and D.L. Jones, IEEE Trans. on Broadcasting, vol. 49, no. 3. pp. 258-268, 2003) is proposed for shaping the clipping noise accordingly. In comparison to conventional clipping techniques a lower out-of-band (OOB) radiation and a smaller E_b/N₀-degradation can be achieved.