Dqpsk wdm

[Urvi pathak]

Hi.
Please guide me in design of 4 channel wdm with each channel has data rate of 10 gbps. In my design I am not getting proper constellation diagram. I m using power from – 15 dbm to +15 dbm..

[aasif bashir dar]

hi urvi pathak,
please can you upload the .osd file or the screen shot of your .osd file.

with regrads

[umer syed]

hi urvi pathak,
no attachments found
with regards

[Dr. Dhiman Kakati]

Hello Urvi pathak,
for getting appropriate result you must be aware of the channel spacing and and side lobe powers (depends on modulation scheme you are using) and accordingly you have to tune the fiber central wavelength. It would must much clear if you upload here with your design then we can look for the problems that might be there in the design. Thanking you…

Regards,
Dhiman

[umer ashraf wani]

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwijne_P08XMAhVD26YKHdUuDBIQFgglMAE&url=http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0030402611005845&usg=AFQjCNHSjyTJRViNNegkbuAPR8Dq1ycaoQ&sig2=kx7PKiGnGoy3o9NdtMyFBg
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwijne_P08XMAhVD26YKHdUuDBIQFggtMAI&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F2220%2F28659%2F01283616.pdf%3Farnumber%3D1283616&usg=AFQjCNGJhxt0k0mu3ACeSCvDK2s_bku1Rg&sig2=N1-vMGSeF2klR3xDHvl8_w
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwijne_P08XMAhVD26YKHdUuDBIQFghSMAc&url=http%3A%2F%2Fwww.copl.ulaval.ca%2Ffileadmin%2Fcopl%2Fdocuments%2Fdocuments%2FPublications-PDF%2FRusch%2Fconf89.pdf&usg=AFQjCNGUvMGgUk7JIBh64iAOpT3RRtzyNQ&sig2=v0_btoqd4eaRLL23UR2HMw
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=0ahUKEwiv3Irj08XMAhUIx6YKHTlcD104ChAWCBowAA&url=https%3A%2F%2Fwww.vde-verlag.de%2Fproceedings-en%2Fgs_proceeding%2F%3Fdocid%3D563042311&usg=AFQjCNEbiAaihmuTMbRvDMzkNtZIKOVIsg&sig2=dVWSA5sNGqWC71KOEG68qg&bvm=bv.121421273,d.dGY
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&cad=rja&uact=8&ved=0ahUKEwiv3Irj08XMAhUIx6YKHTlcD104ChAWCCwwAw&url=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F3293389_Impact_of_nonlinear_phase_noise_on_direct-detection_DQPSK_WDM_systems&usg=AFQjCNHmpm8vvCqhJW7Hi6UAVd3tnPhEEA&sig2=OKA0ECd647MiA3mqqOAg7w&bvm=bv.121421273,d.dGY

[Karan Ahuja]

Hello,
I want to mention that in conventional DQPSK receivers a pair of onebit delay asymmetric Mach-Zehnder interferometers (AMZI) are used: one for the in-phase (I), and one for the quadrature (Q) component. Similar to binary DPSK3, a narrow optical filter can be used instead of each AMZI 4. The frequency response the optical filters should approximate the main lobe of the frequency response of the constructive port of the AMZI. By tuning the central frequency of the filter either the I or Q component of the DQPSK signal can be demodulated. We will call such a receiver a narrow filter (NF) receiver. We experimentally demonstrate in this paper that a single arrayed waveguide grating (AWG) can be used
to simultaneously demodulate the in-phase (or quadrature) component of a comb of DQPSK signals. It can be seen how the AWG filter approximates the main lobe of the theoretical response of the AMZI. The use of AWGs for WDMDQPSK signals represents a big advantage in terms of component counts.
Hope this helps.
regards

[Karan Ahuja]

I am attaching a link of one paper which mentions about the DQPSK. It also says that in the modulation and demodulation methods of the optical differential quadrature phase shift key (DQPSK) and the different modulation formats including nonreturn-to-zero (NRZ), return-to-zero (RZ), carrier-suppressed return-to-zero (CS-RZ) are introduced, studying the different optical signals in the 40 Gb/s high speed transmission system. The system is simulated in 200 km optical fiber by way of dispersion compensation. It is showed that the ability of anti-dispersion and anti-PMD (polarization mode dispersion) is better in the CS-RZ–DQPSK modulation format, and this format has the smallest eye-opening penalty (EOP) with a wider range of power into the optical fiber.
Try to refer to this paper. It will be surely of some help.
http://www.sciencedirect.com/science/article/pii/S0030402611005845
Regards

[Karan Ahuja]

Also try to go through this paper too.
https://www.researchgate.net/publication/3293389_Impact_of_nonlinear_phase_noise_on_direct-detection_DQPSK_WDM_systems

It mentions that the performance degradation of differential quadrature phase-shift keying (DQPSK) wavelength-division-multiplexed (WDM) systems due to self-phase modulation (SPM)- and cross-phase modulation (XPM)-induced nonlinear phase noise is evaluated. The XPM-induced nonlinear phase noise is approximated as Gaussian distribution and summed together with the SPM-induced nonlinear phase noise. Here 10-Gb/s system is demonstrated, whose walk off length is larger than 40-Gb/s systems’, are more sensitive to XPM-induced nonlinear phase noise than 40-Gb/s systems. Furthermore, DQPSK WDM systems show lower tolerance to both SPM- and XPM-induced nonlinear phase noise than differential phase-shift keying WDM systems.
Hope this is what you are looking for.
Regards

[burhan num mina llah]

Hello Urvi,

To be able to help firstly i would suggest you to upload your osd file if possible. Secondly , can you mention the significance that why you have taken power from -15 to +15 dBm?

Regards

Burhan

[Author]

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