CORDIC-based VLSI architecture for implementing CI-OFDM and its FPGA prototype

Abstract

Since decades, orthogonal frequency division multiplexing (OFDM) has been drawing its attention in the area of wireless and satellite communication systems such as IEEE 802.11 a/g/n, ADSL, WiMAX and DVB-T/SH. In these applications, OFDM has drawbacks of high Peak-to-Average Power Ratio (PAPR) and Inter carrier symbol interference (ISI). Recently, Carrier Interferometry OFDM (CI-OFDM) as an alternative to OFDM is being studied to minimize the aforesaid drawbacks. To the knowledge of authors, there is no Field Programmable Gate Array (FPGA) prototyping of CI-OFDM is addressed for real time wireless and satellite communication system. In this context, authors in this paper have proposed a new hardware efficient and flexible CO-ordinate Rotational Digital Computer (CORDIC) based CI-OFDM architecture. The novelty of this proposed architecture is its capability to change the number of orthogonal subcarriers and data symbols upto the maximum 32K, that shall be suitable for most of the standards of wireless and satellite communication system and prototyped using commercially available FPGA device XC3S500E-5FG320. The implementation and experimental results of this proposed scheme are highlighted and validated with the result from MATLAB simulation.