Numerical Analysis of Dynamic SNR Management by Controlling DSP Calculation Precision for Energy-Efficient OFDM-PON

We propose a novel energy-saving technique using a variable precision digital signal processor for an orthogonal frequency division multiplexing (OFDM)-passive optical network. Our technique minimizes energy consumption while satisfying the bit error rate requirements by controlling the calculation precision of fast Fourier transform (FFT) and inverse FFT when generating an OFDM signal. We clarify the feasibility of our proposed technique numerically for QPSK and 16 quadratic-amplitude modulation signals. The simulation results indicate that calculation precision can be reduced according to the transmission distance.