High-speed, Low Cost Parallel Memory-Based FFT Processors for OFDM Applications

Low cost yet efficient FFT (Fast Fourier Transform) processors are greatly needed for real-time operation in many OFDM applications. Taking the advantages of both memory-based and pipelined FFT architectures, this paper presents simple radix-2 memory-based FFT (MBFFT) Processors with low hardware cost and high maximum operation frequency. Results show that the core area of the proposed MBFFT is 1.79mm² with the maximum operation frequency of 205MHz, or a process speed of 269¿s for N=8192 points (24 bits per word). This also implies a throughput of 730 Mb/s (Mbits per second). This paper also presents parallel MBFFT structures with two and four butterfly processing elements (PEs), respectively, to improve the latency while still keeping low hardware cost and high maximum operation frequency.