Iterative Estimation and Cancellation of Clipping Noise for Multi-Layer IDMA Systems

Multi-layer interleave-division multiple access (IDM/IDMA) inherently exhibits a large peak-to-average power ratio (PAPR). Correspondingly, the power amplifier has to operate with a large back-off, which reduces the power efficiency. Clipping at the transmitter side is an efficient and simple method to reduce the PAPR, but causes nonlinear in-band distortions and sometimes out-of-band radiation. In this paper, we propose a novel receiver algorithm to estimate and cancel the clipping noise of multi-layer IDMA signals. The proposed algorithm is based on the fact that the estimated clipping noise and soft decoded symbols can be used to refine each other iteratively. It is shown by simulation that the performance loss due to clipping can be almost completely compensated in most cases.