Enhancing Resilience to Rayleigh Crosstalk by Means of Line Coding and Electrical Filtering

In-band simultaneous transmission of baseband and broadcast signals in wavelength reused bidirectional passive optical network

“…Compared to Manchester coding in [18], 8b10b coding scheme is much more bandwidth efficient due to its low overhead and therefore, used in several research articles including our previous demonstration in [24,25]. Due to the effective suppression of frequency components from DC to $ 1 GHz in 10 Gb/s coded signal, the upstream data with 1.25 Gb/s PRBS can be transmitted over the downstream modulated signal by spectral separation to improve system resilience against re-modulation noise.…”

“…The backscattered noise signal is generated from downstream modulated signal, propagated in upstream direction and mixed with upstream data signal to produce crosstalk noise in US receiver. According to [24], system resilience against crosstalk penalty can be improved by maintaining an acceptable level of signal to crosstalk power ratio (SCR). In this simulation model, the power of DS signal at fiber input was maintained to 0 dBm, which results backscatter noise signal power fixed to À 34 dBm in US [26].…”

“…Due to this fixed noise power in US, the SCR now can be controlled and eventually set to a certain value by varying US signal power through VOA-3. We set the SCR value above 25 dB that ensure minimum system penalty caused by RB noise [24].…”

“…1(c), the 10 Gb/s coded downstream signal has suppressed frequency components from DC to GHz range, and thus re-modulation noise can be minimized by transmitting the upstream data with 1.25 GHz and downstream data with 10 Gb/s in two separate bands. On the other hand, power penalty induced by RB noise is set to minimum label by maintaining the signal to crosstalk power ratio above 25 dB [24].…”

A Rayleigh Backscattering Noise Resilient and Cost Effective Single Fiber WDM-PON Scheme using DQPSK and Intensity Re-modulation Technique

“…modulation [11], cross-seeding scheme in WDM based NGA Q.Guo, noise predictive equalizer with noise canceller for RSOA based WDM-PON [12] and signal re-modulation ring with RB interferometric noise mitigation in WDM-PON [13]. Further techniques based on carrier-distributed WDM-PONs using in-band optical filtering [13], line coding with electrical filtering in PON networks [14], high extinction ratio (ER) IRZ downstream and phase re-modulated DPSK upstream [15] and DPSK downstream and OOK intensity re-modulated up-stream [16] have also been proposed to reduce the influence of RB induced noise in WDM-PON. Although, enhanced resilience against RB induced noise has been observed by these techniques but they reduce effectiveness due to one or more of these reasons, either design complexity, additional components requirements, high deployment cost, limitations of data rate or low receiver sensitivity in downstream and upstream.…”