A Reduced-PAR Opportunistic STBC Scheme for Frequency-Selective Channels in the Presence of Frequency Offset

Opportunistic space-time block codes (STBC) have been investigated for flat-fading channels in the literature. In this paper, we present a novel scheme for integrating them with orthogonal frequency division multiplexing (OFDM) for frequency-selective channels with an unequal error protection capability making it attractive for multimedia and multicasting applications. In addition, our new scheme optimizes the tradeoff between coding gain and peak-to-average ratio (PAR) while minimizing inter-carrier interference in the presence of carrier frequency offset. We show that our scheme achieves a 2 dB reduction in PAR over the conventional scheme.