Baseband OFDM and ultrawide band OFDM signals coexistence requirements for extended reach PONs

A first analysis of a transmission solution for providing Gigabit data access jointly with wireless high definition television down streaming (using orthogonal frequency division multiplexing - OFDM signals) on extended reach passive optical networks is investigated. The optimum power levels assigned to each OFDM signal in the proposed solution are obtained by numerical simulation. The coexistence of the two signals is shown however only up to 30 km of standard single mode fibre and a high optical signal to noise ratio 34 dB is required to obtain a bit error probability of 10^-12. These values still need improvement for practical system implementation. It is shown that the high OSNR requirement is imposed by the baseband OFDM signal and that the power fading resulting from the fibre dispersion limits the system transmission range to the 30 km mentioned before.