ON THE PAR REDUCTION OF MB-OFDM ULTRA-WIDEBAND SIGNALS

摘要

The Peak to Average power Ratio (PAR) of a Multi-Band Orthogonal Frequency-Division Multi-plexing (MB-OFDM) Ultra-Wide Band (UWB) signals can be substantially larger than that of single carrieror carrier-less ultra-wideband signals. In this letter, a novel PAR reduction scheme for the MB-OFDM UWBsystem based on spreading and interleaving is proposed. By spreading the coded bits over each subcarrier incorresponding band and interleaving the spread symbols across all bands, the PAR statistics of theMB-OFDM signals can be improved and the PAR is reduced obviously. In the PAR reduction scheme, there isno loss in transmission data rate or Bit Error Rate (BER) performance decreasing. Since the spreading andinterleaving operation are implemented by unitary Hadamard sequences and used for an approach to providethe robustness of the UWB system to narrowband interference, there is no additional implementation burden.Simulation results show that the investigated scheme gives the PAR reduction of 3dB compared with that ofthe original MB-OFDM signals.