We propose two novel transmitter configurations for generation of linear and non-linear phase modulated optical minimum shift keying (MSK) signals based on approaches of continuous phase frequency shift keying (CPFSK) and I-Q component structure of offset/staggered DQPSK formats. The precoder for I-Q optical MSK structure is derived. The direct detection of optical ligtwave is utilized with implementation of the well-known differential non-coherent balanced receivers. Simulated spectral characteristics and dispersion tolerance to 40 Gb/s transmission are presented and compared to those of ASK and DPSK counterparts.
We report the BER performance characteristics of 16-ary Multi-level Amplitude-Differential Phase Shift Keying
(MADPSK) modulation formats. The modulation scheme is bandwidth efficient with an effective transmission symbol
rate equal to 1/4 of the bit rate. The BER performance of NRZ and RZ MADPSK formats are investigated for long haul
optically amplified transmission in the presence of optical noise, fiber residual chromatic dispersion and non-linearity.
The generation and detection of linear, weakly non-linear and strongly non-linearly optical MSK long-haul transmission systems have been reported. The simulation test-beds based on Matlab Simulink platform have been successfully developed. The following significant results have been achieved: (i) BER of <i>10<sup>-38</sup></i> is achieved for an OSNR of 22.2dB; (ii) At BER of <i>10<sup>-12</sup></i>, linear MSK is approximately 1 dB more tolerable to nonlinearity than weakly nonlinear MSK and 5.5dB more durable than strongly nonlinear MSK; (iii) (c).The sideband suppression ratio for linear MSK is approximately 22dB. New technique for calculation of performance evaluation implementing expected maximization (EM) theorem is utilized.
We report the transmission of 40Gb/s channels over DWDM optically amplified communications systems employing RZ, NRZ, CS-RZ amplitude and differential phase shift keying modulation over 320 km standard SMF and 328 km dispersion compensating modules. Impacts of optical filtering of 10 Gb/s DWDM transmission system on these 40G modulation formats are reported. The mutual impacts of 10 Gb/s and 40 Gb/s co-transmission are proven to be minimum.