VLSI design and implementation of reconfigurable OFDM transceivers for software defined radio

This paper presents a software-defined radio (SDR) system with reconfigurable architecture for wireless communications. The baseband software implementation by using a low-power fixed-point digital signal processor (DSP) is applied to demonstrate the concept of SDRs for different standards, and different operational modes. For simplicity, two operational modes, quadrature amplitude modulation (QAM) and quadrature phase shift keying (QPSK) of OFDM baseband transceivers are implemented. The interoperability and adaptability among these operational modes of this OFDM System is discussed. Both modes employ radix-2 decimation-in-time fast Fourier transform (FFT) algorithms. The architecture presented is implemented using a hardware description language (verilog HDL) code. The outcome of the implementation is a portable, scalable, quickly adaptable and reconfigurable system which supplies a high quality signal.