A flexible FFT processor

In this paper a flexible FFT processor for OFDM systems is presented. In future wireless systems using OFDM each terminal should be able to handle a wide range of different applications, from pure voice communication to high-speed data transfers, with as little overhead in power consumption and protocol procedure as possible. As the terminals will be battery powered and should be cheap to manufacture an ASIC solution is required. To be able to adapt to different communication schemes and various communication channels the FFT processor must be configurable. To minimize power consumption no more precision than necessary should be used. A pipelined radix22 FFT processor, with the possibility of run time switching between 32-1024 points, have been designed in a standard CMOS 0.35 µm technology. Clock gating and low power memories have been used to reduce power consumption