For the calculation of the MFB for channels with a separable time-variant transfer function a method is introduced that significantly reduces the complexity of computation. The basic principle is to apply a scrambling operation to several OFDM frames. For signals from different cells, mutually random scramblings are used to reduce their correlation. This alleviates the worst case inter-cell interference problem. The spreading code is designed in the frequency domain.
Many publications deal with the frequency domain processing.
The disadvantage of this guard interval is the higher hardware complexity and the waste of symbol energy. In the following paper the effect of ISI on a MC-SS system is investigated. Simulation results confirm our analysis and show the importance of the analytical tool to perform realistic system analysis without having to resort to time consuming time-domain simulations. This paper deals with the application of spread spectrum techniques to MultiCarrier HF modems. OFDM modems are a special option for the transmission over the high dispersive HF medium in front of single carrier modems.