Block codes for frequency diversity and peak power reduction in multicarrier systems

The block coding scheme which is capable of both peak-power reduction of multicarrier signals and error correction is applied to multipath fading channels. As long as the channel is frequency-selective, considerable coding gain can be achieved, due to the frequency diversity effect. In practice, however, the guard interval is often shorter than the maximum delay spread, which causes an irreducible error door due to the intersymbol interference (ISI). As for coded cases with a short guard interval, the error floor may be still observed, even though the resultant error floor is much lower than the uncoded cases. To remedy this problem, additional Reed-Solomon (RS) codes are concatenated to the system.