Reconfigurable two-dimensional pipeline FFT processor in OFDM cognitive radio systems

Cognitive radio recognizes the situations of radio utilization and propagation environment. It can improve frequency utilization efficiency and communication quality by adapting itself to communication environments. This paper proposes a new architecture for pipeline FFT processors with multi-stream processing in OFDM cognitive radio. The proposed design connects data paths in FFT stages by two-dimensional arrays. The reconstruction of butterfly blocks and FIFO memory blocks gives high circuit utilization and small circuit area. The proposed processor reduced logic elements and memory bits by 26.6% and 45.0% respectively in the FPGA synthesis results.