Implementation of application-specific DSP for OFDM systems

This paper describes implementation of an application-specific DSP for OFDM modem systems. The proposed instructions can support computations of various blocks in OFDM systems. The Data ALU is specially designed and optimized for the proposed instructions. Performance comparisons show that the number of clock cycles improves over 10 % compared with Carmel DSP and over 50 % compared with TMS320C62X for FFT computation. However, the size of the DSP is much smaller than existing DSPs. The proposed architecture is implemented using pPROVE FPGA board and verification is performed using assembly programs that implement most of OFDM blocks. The SQNR value of FFT output is about 71 dB.