Randomized OFDM for Multi-cell Environments1

This paper is concerned with a randomized OFDM (R-OFDM) scheme. The basic principle is to apply a scrambling operation to several OFDM frames. With a proper design strategy, the scrambling operation will not affect intra-cell orthogonality of OFDM (even considering multi-path effect). For signals from different cells, mutually random scramblings are used to reduce their correlation. This alleviates the worst case inter-cell interference problem. R-OFDM combines some advantages of both OFDM and CDMA, namely, intra-cell interference avoidance, cross-cell interference mitigation as well as simple receiver structure.