Power-Efficient Continuous-Flow Memory-Based FFT Processor for WiMax OFDM Mode

This paper presents a fast Fourier transform (FFT) processor suitable for IEEE 802.16e (WiMax) OFDM mode. FFT/IFFT processors are very crucial in OFDM transceivers and they usually consume considerable power as well as occupy large area. The proposed FFT processor combines the pipelined architecture and the memory-based architecture so that it can operate at the sample rate and thus achieve power efficiency. The processor is based on the multipath delay commutator architecture with high-radix arithmetic units and two main memories for input buffering, intermediate storage, and output reordering. A proposed conflict-free memory addressing strategy makes possible continuous-flow FFT processing. Simulation results show that it achieves a 29% saving in power consumption.