Research

Research Contribution

The main contribution of my research was to mitigate the challenge of increasing the array aperture lengths from a limited number of array elements to achieve the highest possible resolution. 

An optimal coprime structure is designed which is named as VECADS to form a larger size continuous virtual array using only the basic configuration of coprime array by concurrently exploiting the difference and sum co-array without the need of additional array elements or frequencies at low-cost. 

An optimal new augmentation technique with Translocated and Axis Rotated Compressed Subarrays (CATARCS) is designed on the coprime array concept to enhance the resolution of DOA estimation as well as the DOF. These outputs are obtained by a rank-incremented iterative power factorization interpolation technique. Larger number of degrees of freedom is achieved by extending the autocorrelation matrix applying Iterative Power Factorization algorithm for interpolation; first time used successfully in this work. IPF has promising potential for practical matrix-recovery problems. 

A novel array structure exploiting coprime arrays is proposed which can be very proficient to determine the number of consecutive lags in proportion with the number of array elements. The proposed method comprises novel array structure by configuring three subarrays positioned in alignment with some prescribed values and the final appended one more subarray is to exploit fourth order difference coarray. In this method, full co-array lags have been used by extracting all the lags in first operation of second order difference co-array by applying NNM to interpolate the holes. 

A novel configuration of array structure with three linear coprime subarrays is designed to propose the ability of achieving the maximum degrees of freedom thanthe-state-of-the-art which could be very prone for high resolution DOA estimation. Afterwards, the previous structure was modified by appending one more subarray with exploitation of fourth order difference co-array. By adding fewer number of sensors in subarray 4 larger lags can be achieved which provides us facilities of setting up subarray 4 in limited space which could be very fruitful to cope up with space and cost optimization in special cases where these arise as a big concern. 

Journal Publication

• International Journal

1. T. H. A. Mahmud, Z. Ye, K. Shabir, R. Zheng and M. S. Islam, "OffGrid DOA Estimation Aiding Virtual Extension of Coprime Arrays Exploiting Fourth Order Difference Co-Array With Interpolation," in IEEE Access (IF: 4.098), vol. 6, pp. 46097-46109, 14 August 2018. doi: 10.1109/ACCESS.2018.2865419, [SCI: GU3AB][EI: 20183405722383]. 

2. Tarek Hasan AL MAHMUD, Zhongfu YE, Kashif SHABIR, Yawar Ali SHEIKH, DOA Estimation of Quasi-Stationary Signals Exploiting Virtual Extension of Coprime Array Imbibing Difference and Sum CoArray, IEICE Transactions on Communications (IF: 1.090), 2018, Volume E101.B, Issue 8, Pages 1876-1883, August 01, 2018, https://doi.org/10.1587/transcom.2017EBP3375, [SCI: GT0QL]. 

3. T. H. A. Mahmud, K. Shabir, R. Zheng and Z. Ye, "Interpolating Coprime Arrays With Translocated and Axis Rotated Compressed Subarrays by Iterative Power Factorization for DOA Estimation," in IEEE Access (IF: 4.098), vol. 6, pp. 16445-16453, 7 February 2018. doi: 10.1109/ACCESS.2018.2803050, [SCI: GC9GF] [EI: 20180704790505]. 

4. Hossain, M.I., Al Mahmud, T.H., Islam, M.S. et al. Dual transform based joint learning single channel speech separation using generative joint dictionary learning. Multimed Tools Appl, (2022), (IF: 2.757), 02 April 2022. https://doi.org/10.1007/s11042-022-12816-0. 

5. Kashif Shabir, Tarek Hasan Al Mahmud, Rui Zheng and Zhongfu Ye, “Generalized Super-resolution DOA Estimation Array Configurations’ Design Exploiting Sparsity in Coprime Arrays”. Circuits, Systems & Signal Processing (CSSP) (IF: 1.922), pp. 1-16, 04 March 2019. doi: https://doi.org/10.1007/s00034-019-01078-1. 

6. Rui Zheng, Xu Xu, Zhongfu Ye, Tarek Hasan Al Mahmud, Jisheng Dai, Kashif Shabir, Sparse Bayesian learning for off-grid DOA estimation with Gaussian mixture priors when both circular and non-circular sources coexist, Signal Processing (IF: 4.086), Volume 161, August, 2019, Pages 124-135, https://doi.org/10.1016/j.sigpro.2019.03.021. 

7. Kashif Shabir, Tarek Hasan Al Mahmud, Rui Zheng, Zhongfu Ye. A low-complexity RARE-based 2-D DOA estimation algorithm for a mixture of circular and strictly noncircular sources. Turkish Journal of Electrical Engineering & Computer Sciences, (IF: 0.625), 26(5), pp. 2234-2245, 28 September 2018, https://doi.org/10.3906/elk-1803-76. [EI: 20184105930101]. 

8. Islam, M.S.; Al Mahmud, T.H.; Khan, W.U.; Ye, Z. Supervised Single Channel Speech Enhancement Based on Dual-Tree Complex Wavelet Transforms and Nonnegative Matrix Factorization Using the Joint Learning Process and Subband Smooth Ratio Mask. Electronics (IF: 2.110), 22 March 2019, 8(3), 353. doi:10.3390/electronics8030353. 

9. Islam, M.S., Al Mahmud, T.H., Khan, W.U. et al. “Supervised Single Channel Speech Enhancement Based on Stationary Wavelet Transforms and Non-negative Matrix Factorization with Concatenated Framing Process and Subband Smooth Ratio Mask”, J Sign Process Syst. (IF: 1.035) 2019, https://doi.org/10.1007/s11265-019-01480-7. 

10. Tarek Hasan Al Mahmud, Kashif Shabir, Rui Zheng, Zhongfu Ye and Md Shohidul Islam, “A Novel Array Structure with Higher DOF comprising Triplet Coprime Arrays for High Resolution DOA Estimation”. Submission under process. Digital Signal Processing Journal (IF: 2.241) 

11. Kashif Shabir, Zhongfu Ye, Tarek Hasan Al Mahmud, Yawar Ali Sheikh and Rizwan Ullah, “Efficient Underdetermined DOA Estimation Algorithm by Extending Covariance Matrix Based on Non-Circularity using Coprime Array”, Communications on Applied Electronics (CAE), Vol.7, No.1, Pages 1-5, May. 2017, doi: 10.5120/cae2017652580. 

12. Yawar A. Sheikh, Zhongfu Ye, Kashif Shabir, Tarek Hasan Al Mahmud, Rizwan Ullah, 2-D Near Field Source Localization by Evolutionary Technique Exploiting the L-Type Geometry of Sensor Array, Circulation in Computer Science(CCS), Vol.2, No.3, Pages 11-16, Apr. 2017, doi: 10.22632/ccs-2017-251-64. 

13. Khandaker Takdir Ahmed, Dr. Tarek Hasan Al Mahmud, Md. Jashim Uddin, Md. Mustakim Musully Pias, “A Novel AODV AODV-Based Algorithm to Improve MANET Efficiency and Performance”, International Journal of Scientific & Engineering Research, Volume 13, Issue 7, July-2022, ISSN 2229-5518. 

14. Dr. Tarek Hasan Al Mahmud, Khandaker Takdir Ahmed, Md. Jashim Uddin, Md. Abdul Aziz, Md. Abu Jubaer Rupok, Md. Mustakim Musully Pias, Debashis Biswas, “An Approach to Increase the Network Life Time of Wireless Sensor Network for Heterogeneous Node using Particle Swarm Optimization (PSO) Algorithm and Genetic Algorithm (GA)”, IOSR Journal of Electronics and Communication Engineering (IOSRJECE), Volume 17, Issue 4, Ser. I (Jul. – Aug. 2022), PP 08-19, e-ISSN: 2278-2834, p-ISSN: 2278-8735. 

15. Khandaker Takdir Ahmed1, Dr. Tarek Hasan Al Mahmud, Md. Jashim Uddin, Md. Mustakim Musully Pias, “A Novel AODV AODVBased Algorithm to Improve MANET Efficiency and Performance”, International Journal of Scientific & Engineering Research, Volume 13, Issue 7, July-2022, ISSN 2229-5518. 

16. Khandaker Takdir Ahmed, Dr. Tarek Hasan Al Mahmud, Md. Jashim Uddin, Md. Mustakim Musully Pias, “Improve the Performance of AODV-SOS and FORP-SOS Routing Protocols in MANET for Emergency Rescue Services Based on Obtained Signal Intensity”, International Journal of Scientific & Engineering Research Volume 13, Issue 5, May-2022 1051 ISSN 2229-5518. 

17. Tarek Hasan-Al-Mahmud, Dr. M. Mahbubur Rahman, Sumon Kumar Debnath, “Performance Analysis of Best suited Adaptive Equalization Algorithm for Optical Communication” Published in Journal of Telecommunications (ISSN 2042-8839), Volume 1, Issue 2, PP. 35-41, Mrach 2010. 

18. Md. Mainul Islam Mamun, Tarek Hasan-Al-Mahmud, Sumon Kumar Debnath and Md. Zahidul Islam, (2010) “Analyzing the Low Power Wireless Links for Wireless Sensor Networks”, Journal of Telecommunications (ISSN 2042-8839), Volume 1, Issue 1, PP. 123-126, February 2010, https://doi.org/10.48550/arXiv.1002.4838. 

19. Dr. M. Mahbubur Rahman, Md. Khairul Islam, Tarek Hassan-Al-Mahmud, A. R. Mahmud “Performance Analysis of Downlink Power Control in WCDMA System” International Journal of Scientific & Engineering Research, ISSN 2229-5518, Volume 3, Issue 8, August-2012. 

20. Dr. M. Mahbubur Rahman, Md. Amzad Hossain, Tarek Hasan-Al-Mahmud and A. R. Mahmud “Performance Analysis of Channel Assignment Scheme in Wimax” IOSR Journal of Electronics and Communication Engineering (IOSRJECE) ISSN : 2278-2834 Volume 1, Issue 6, PP 24-30, July-Aug 2012, doi:10.9790/2834-0162430. 

• Domestic Journal

21. Paresh Chandra Barman, Tarek Hasan-Al-Mahmud, Bikash Chandra Singh. Classification and Identification of Meaningful Gene Using NonNegative Matrix Factorization. Journal of Applied Science and Technology, Vol. 8,No.1, June 2012, pp 57-64,ISSN 2218-481X. 

22. Tarek Hasan-Al-Mahmud, Ashadun Nobi, M. Zamil Sultan, M. Mahbubur Rahman. Improving Stability, Steady-State Error Performance And Convergence Rate In Optical Communication Implementing AFS-MDFE Using ADG And TD Algorithm. Journal of Green World Foundation, ISSN 2076-3972, Inst.eng.tech. 1(1):21-29 January, 2010. 

23. Sumon Kumar Debnath, Tarek Hasan-Al-Mahmud, “Efficient Group Communication in Mobile Ad-hoc Network. Published in Journal of Green World Foundation, ISSN 2076-3972, Inst.eng.tech. 1(1):21-29 January, 2010 

24. Ashadun Nobi, Tarek Hasan-Al-Mahmud, “A fast monte carlo simulation for site percolation using hoshen-kopelman algorithm and canal search algorithm”. published in Computer Science and Engineering Research Journal(CSERJ), Vol. 05 (2008). ISSN: 1990-4010 Chittagong University of Engineering and Technology.(CUET) 

25. A. Nobi and T. Mahmud, “Determination of Fractal Dimension of the Stochastic Cantor Set Using Monte-Carlo Simulation and a Comparison with Analytical Solution”. Accepted for Journal of Computer Science, Volume 2, Number 1 & 2, December 2008. IBAIS University. 

26. A. Nobi and T. Mahmud, “Determination of Fractal Dimension of the Random Stochastic Cantor Set Using Monte-Carlo Simulation and a Comparison with Analytical Solution”. Accepted for Official Journal of Bangladesh Physical Society, ISSN 1816-1081. 

27. M. Zamil Sultan, Dr. Anis Ahmed, Ashadun Nobi, and Tarek Hasan, Analysis of the Characteristics of Triangular Corrugated Optical Waveguide, Published in Journal of Green World Foundation, ISSN 2076-3972, Inst.eng.tech. 1(1):9-15 January, 2010. 

• Conference Paper

28. Tarek Hasan-Al-Mahmud, Dr. M. Mahbubur Rahman “Performance Analysis of AFS-MDFE with ADG and TD Algorithm for the Equalization in Optical Communication”. National Conference on Communication and Information Security (NCCIS). Daffodil University, Dhaka, Bangladesh. 23-24 November 2007, Bangladesh. Published as conference proceedings with 6 pages (from 49 to 54). 

29. Design and Simulation of OFDM and Analyzing the Performances Comparing with QAM systems. Tarek Hasan-Al-Mahmud, M. Mahbubur Rahman and Tapan Kumar Godder National Conference on Electronics, Information and Telecommunication(NCEIT),Bangladesh Electronics Society (BES), 29-30, June,2007 Bangladesh page no. 122 ISBN-984-300-000645-7. 

• Books

30. “Information and Communication Technology” by Tarek Hasan-Al-Mahmud and Jashim Uddin. Bangla enlarged version text & reference book of Information and Communication Technology for eleventh and twelfth classes approved by National Curriculum and Text Book Board of Government. 

31. “Information and Communication Technology” by Tarek Hasan-Al-Mahmud and Jashim Uddin. Bangla version Lab book of Information and Communication Technology for eleventh and twelfth classes approved by National Curriculum and Text Book Board of Government. 

32. “Information and Communication Technology” by Tarek Hasan-Al-Mahmud and Jashim Uddin. English version textbook of Information and Communication Technology for eleventh and twelfth classes approved by National Curriculum and Text Book Board of Government. 

33. “Information and Communication Technology” by Jashim Uddin, Tarek Hasan-Al-Mahmud and Engr. Anuj Biswas. Bangla version textbook of Information and Communication Technology for eleventh and twelfth classes approved by National Curriculum and Text Book Board of Government.