POSTGRADUATE PROGRAM

Optical Communication and Networks Group (OCNG)

Principal Investigator: Engr. Farhan Qamar

Research Themes

• Fiber Optic Communication
• Ultra High Bit Rate Date Transmission
• Long Haul Communication > 1200km
• Non-Linearities and Fiber Dispersion
• Advanced Modulation Formats i.e. OFDM, QAM and POLMUX-QPSK
• Non-linear Schrodinger Equation (NLSE)
• Digital Backward Propagation
• Link Design Methodologies
• Access and Metro Networks
• All-Optical Signal Processing

Software

• OptiSystem v.12
• MATLAB v.2013a

Summary

The requirements for bandwidth and capacity in metro and long-haul optical communication systems due to the demands of high-speed data services, internet video services, data centers and higher bandwidth residential broadband connections, are exponentially increasing. Recent advancements in high data-rate optical transmission systems have triggered an intensive investigation in digital signal processing (DSP) algorithms as well as in spectrally efficient advanced modulation formats. Coherent optical quadrature phase shift keying (CO-QPSK) is considered as the strongest candidate for implementing 100GbE networks due to its relatively low OSNR requirements and can have spectral efficiency (SE) of 2.2b/s/Hz in case of DP-RZ-QPSK. In order to meet the ever-increasing demand of capacity requirements, increase in SE of the transmission system can be a possible solution. Most recently advanced modulation formats; M-quadrature amplitude modulation (QAM) [M=4,16,32,64, 256 and 1024] and orthogonal frequency-division multiplexing (OFDM) have been investigated in order to increase the SE. However, this high SE is obtained at the expense of complicated transmitter structures, i.e. OFDM, and dense constellation diagrams, i.e. M-QAM (where M=16,32,64, 128 etc), which collectively make them less robust against fiber transmission impairments i.e. chromatic dispersion (CD) and non-linearities (NL).

Group Members

• PhD Candidates
Engr. Humayun Shahid: OFDM+Long-Haul Networks
Engr. Ali Riaz: OFDM+Multimode
Engr. Farhan Qamar (co-supervisor): Chaos Communication

• MS Full-Time Candidates
Javeria Yasemin (2k12 Session): Gain Amplifiers
Marriam Imtiaz (2k12 Session): Long-Haul Networks
Maria Nazir (2k12 Session): Access Networks (PONs)
Ramshah Ahmed (2k13 Session): Solar Cells
Rabeea Basir (2k13 Session): MIMO Transmission

• BE Final Year Projects (FYPs)
Ist Group: Hybrid Opto-Wireless Networks
2nd Group: Advanced Modulation Formats
3rd Group: DSP Algorithms for Coherent Receivers

Publications (Nov 2012-Onwards)

Journal Publications

1. Rameez Asif, Ghulam Shabbir and Adeel Akram "Hybrid Mid-Link Spectral Inverter to Compensate Linear and Non-linear Distortions for Efficient Transmission Performance in 224Gbit/s DP-16QAM System," SPIE Optical Engineering, August 2013.

2. Rameez Asif, Humayun Shahid, Farzana Arshad and Rashid Saleem, "Scalable Non-linear Equalization in High-Bit-Rate Optical Transmission Systems," Journal of Photonics Research (Optical Society of America (OSA)), September 2013.

3. Lubna Nadeem and Rameez Asif, "FSK signal generation with wavelength reuse capability in 8Gbit/s radio over fiber systems," Optoelectronics, DOI:10.1007/s12200-013-0331-0, July 2013.

4. Bushra Nawaz and Rameez Asif, "Impact of polarization mode dispersion and non-linearities on 2 channel DWDM chaotic communication systems," Optoelectronics, DOI: 10.1007/s12200-013-0332-z, June 2013.

5. Rameez Asif, Muhammad Khawar Islam and Muhammad Zafrullah, "All-optical Signal Processing of Fiber Impairments in Dual-polarization 112Gbit/s m-ary QAM Coherent Transmission," Journal of Optical Society of Korea (JOSK), Vol 17, No.1, February 2013.

6. Rameez Asif, Chien-Yu Lin, Michael Holtmannspoeter and Bernhard Schmauss, "Evaluation of Correlative Coding and DP-16QAM N-channel 112Gbit/s Coherent Transmission: Digital Non-linear Compensation Perspective," Optics Express, Vol. 21, Issue 1, pp. 781-788, January 2013.

Conference Publications

1. Rameez Asif, Adeel Akram and Ghulam Shabbir, “Distributed In-line Mitigation of Optical Kerr Effects for 100GbE Transmission Systems, 18th OptoElectronics and Communications Conference (OECC 2013), Kyoto Japan, June 2013.

2. Rameez Asif, Chien-Yu Lin and Bernhard Schmauss, “Numerical Evaluation of Robust and Spectrally Efficient 112Gbit/s Transmission Employing Digital Backward Propagation, Photonics Global Conference (PGC), Singapore, December 2012.

3. Rameez Asif, Chien-Yu Lin and Bernhard Schmauss, “Non-UniformStep-Size based Split Step FourierMethod for Mitigating Fiber Transmission Impairments in N-Channel 224Gbit/s PolMux-16QAM System, 18th IEEE International Conference on Networks (ICON), Singapore, December 2012.

4. Rameez Asif, Muhammad Khawar Islam and Muhammad Zafrullah, “Analysis and Application of Scalable Non-linear Equalization in 112Gbit/s DP- 64QAM Coherent Transmission over Single Mode Fibers, Photonics Global Conference (PGC), Singapore, December 2012.

5. Rameez Asif, Muhammad Khawar Islam and Muhammad Zafrullah, “Effective Negative Kerr Non-linear Coefficient Using Highly Non-linear Fibers: A Scalable Backward Propagation Approach, 18th IEEE International Conference on Networks (ICON), Singapore, December 2012.

Citation Index

http://scholar.google.com/citations?user=6OWh3IIAAAAJ