A power-of-two FFT algorithm and structure for DRM receiver

Digital Radio Mondiale (DRM) is the most important technology to replace analog AM broadcasting into digital one. The core of DRM is based on coded orthogonal frequency division multiplexing (COFDM), so it has high spectrum efficiency including the other advantages. Modern OFDM is based on discrete Fourier transform (DFT) or inverse discrete Fourier transform (IDFT). However, due to the particularity of DRM, the numbers of sub-carriers in four DRM robust modes are not same. And these numbers are nonpower- of-two. Typically, the fast Fourier transform (FFT) is based on a power-of-two algorithm. We do have some algorithms to compute the non-power-of-two FFT such as the prime-factor algorithm (PFA). However, these algorithms are complex and inconvenient to implement. Therefore, we propose a new algorithm and structure to use a power-of-two FFT algorithm in DRM receiver. This algorithm has low complexity, more general and flexible characteristics. In the end the paper gives out the bit error rate (BER) simulation results, these results indicate that the proposed algorithm's performance is same as the traditional one.