Performance Analysis Under Double Sided Clipping and Real Time Implementation of DCO-GFDM in VLC Systems

In the context of visible light communications (VLC), DC biased optical generalized frequency division multiplexing (DCO-GFDM) is a recently emerged waveform relying on block based transmission and employs pulse shaping using a circularly rotating prototype filter. In this work, we analyze the bit error rate (BER) performance of DCO-GFDM under double sided clipping induced by front end light emitting diode (LED) transmitters. The effect of clipping on BER performance is studied under different biasing conditions for different prototype filters. Additionally, we experimentally verify the real time performance of DCO-GFDM using different pulses. Simulations are performed in MATLAB software and experiments are conducted in a Lab-view environment using hardware. Two independent universal software radio peripherals (USRP)s are utilized as transmitter and receiver boards. It is observed that the simulation results match well with the corresponding theoretical results. Meanwhile, the experimentally achieved results for error vector magnitude (EVM), the received constellations, and the received spectrum along with BER in different cases are presented for the validation of DCO-GFDM waveform and are compared with DCO orthogonal frequency division multiplexing (DCO-OFDM).