Novel low power pipelined FFT based on subexpression sharing for wireless LAN applications

This paper proposes a novel low power multiplierless radix-4 single-path delay commutator (R4SDC) FFT processor architecture for wireless LAN (IEEE 802.11 standard) applications, where short FFT are utilised in the implementation of the physical layer. The multiplierless architecture uses shift and addition operations to realize complex multiplications. By combining a new commutator architecture, and low power butterfly architectures with this approach, the resulting power savings are around 19% and 35% for 64-point and 16-point radix-4 FFT respectively, as compared to a conventional FFT architecture based on non-Booth coded Wallace tree multiplier.