This paper presents a high-throughput,hybrid word-length,mixed-radix,four-parallel data-path 128-point FFT/IFFT processor for MB-OFDM ultrawideband(UWB)systems.The proposed processor uses an error compensation method for modified booth fixed-width multipliers and canonic signed digit(CSD)multipliers,which leads to higher precision and lower hardware complexity.From analysis,it is shown that the proposed architecture can save 49% multipliers utilizations compared to MRMDF architecture,additional our proposed architecture can save 30% memory resource and be increased by 33% throughput rate compared to the two- parallel data-path architecture under the same hardware cost.So it makes the best balance of the precision,the hardware cost and the speed.Also,ours processor is designed using 0.18 μm COMS process with a throughput rate of up to 1.2 Gsample/s at 300 MHz,which meets the requirements for gigabit WPAN.