BER estimation in DPSK systems using the differential phase Q taking into account the electrical filtering influence

A novel method to estimate the bit-error ratio (BER) in differential phase-shift keying systems, taking into account the receiver electrical filtering influence is proposed. This method assumes a Gaussian distribution for the "equivalent" differential phase evaluated after electrical filtering. The validity of the proposed method is assessed by comparison with results from Monte-Carlo simulation, in systems where the amplified spontaneous noise added by the in-line erbium-doped fiber amplifiers is prevalent over the remaining noise sources. A good agreement between the estimates of the proposed method and results from Monte-Carlo simulation is shown. The proposed method correctly estimates the BER improvement due to the electrical filtering.