Superposition by Position

We present a novel method for superposition coding applicable to OFDM systems in which the receivers being transmitted to are one high SNR receiver and one low SNR receiver. The degradation of the high SNR receiver, however, results primarily from channel uncertainty. Thus, we consider the effect of imperfect channel estimates, a ubiquitous problem in mobile wireless, and show that the new scheme performs much better than traditional schemes in such a setting.