Diversity Combining for Layered Asymmetrically Clipped Optical OFDM Using Soft Successive Interference Cancellation

In this letter, we present a novel diversity combining receiver for demodulating layered asymmetrically clipped optical orthogonal frequency division multiplexing. The receiver consists of a soft successive interference cancellation (SIC) module which cancels the inter-layer interference (ILI) using the minimum mean square error (MMSE) estimates of the information symbols, and a diversity combining module which extracts the diversity components from the clipping noise. We show that the soft SIC module alone can effectively suppress the ILI, leading to bit error rates (BERs) resembling those of a genie receiver which is free of error propagation. It is also shown that the diversity combining receiver which combines the MMSE estimates with their diversity components outperforms the genie receiver by up to 2 dB at the BER of 10
^-6
.