A scalable FFT processor architecture for OFDM based communication systems

Abstract

The modern wireless standards predominantly are based on OFDM communication systems. Various mobile devices in recent times support multiple wireless standards and demand efficient transceiver. Hence, in a communication transceiver the baseband hardware needs to be scalable and efficient across multiple standards. In an OFDM based transceiver, FFT computation is one of the most computationally intensive and power hungry modules. Design of FFT hardware is a challenging task while balancing design parameters such as speed, power, area, flexibility and scalability. The research work in this paper proposes a scalable radix-2 N-point novel FFT processor architecture. The architecture design is based on an approach to balance various specified design parameters to meet the requirements of SDR platforms supporting multiple wireless standards. The FFT processor was designed and prototyped using VHDL on an Altera Stratix V FPGA device 5SGSMD5K2F40C2. The processor operates at a maximum frequency of 200MHz, uses less than 1% of FPGA device resources and meets the performance requirements of multiple wireless standards such as IEEE 802.11a/g, IEEE 802.16e, 3GPP-LTE, DAB and DVB. The proposed architecture outperforms the existing fixed and variable length FFT processors in terms of speed, flexibility and scalability.