High performance 2048 point FFT/IFFT design for IEEE 802.16e standard

The IEEE 802.16e is a standard for mobile Wi-MAX (worldwide interoperability for microwave access). It uses an OFDMA technology. OFDMA improves OFDM robustness to fast fading & narrowband co-channel interference. OFDMA can be used in mobile Wi-MAX communication because of its low transmission power and high speed for low data rate user simultaneously sends. In the widely used OFDMA systems, the FFT and IFFT pairs and PSK or QAM are used to modulate and demodulate the data constellation on the sub carriers. Radix-2
²
algorithm proposed and used for the OFDMA communication systems. In the 2048 point pipelined FFT, the input values are split into two groups of size 1024 in the initial radix-2 stage. The second stage produces four groups containing 256 values each. The outputs from the second butterfly stage have to be stored in a buffer. The design will be coded in VHDL language and targeted into FPGA kit.