volume | PIER Journals

Abstract

Switched beamforming using electronic phase shifters is commonplace. Digital switched beamformers offer a premise of better performance than electronic phase shift switched beamformers. It is also worth noting that current unknown signal Direction of Arrival (DoA) estimation methods (commonly MUltiple SIgnal Classification (MUSIC) and Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT)) are generally computationally intensive. In this paper, signal DoA estimation and digital switched beamforming using aptly designed Artificial Neural Network (ANN) classifiers are looked into. Initially, signals detected at a rectangular receiving array are mapped onto a DoA through an ANN classifier. A second ANN classifier maps the selected DoA onto an optimal set of beamforming weights leading to an optimal switched beamforming reception pattern. The ANN classifiers' performance in DoA estimation and beamforming is tested over a variety of trials, yielding good results. The designed ANN beamformer premises to yield high-speed and accurate switched beamforming performance, most notably in large array systems. The ANN DoA estimator/beamformer can be easily adapted to non-uniform arrays wherein closed form DoA estimation/beamforming solutions are impractical. MATLAB software environment has been used as the main analysis tool.

1. Gross, F. B., Smart Antennas for Wireless Communications, 2nd Ed., McGraw-Hill, New York, 2015.

2. Chand-Godara, L., Smart Antennas, 1st Ed., CRC Press, Boca Raton, Florida, 2002.

3. Allen, B. and M. Ghavami, Adaptive Array Systems Fundamentals and Applications, 1st Ed., John Wiley and Sons, Hoboken, New Jersey, 2005.

4. Tseng, C. H., C. J. Chen, and T. H. Chu, "A low-cost 60-GHz switched-beam patch antenna array with butler matrix network," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 432-435, 2008.
doi:10.1109/LAWP.2008.2001849

5. Wang, H., Z. Zhang, Y. Li, and M. F. Iskander, "A switched beam antenna with shaped radiation pattern and interleaving array architecture," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 7, 2914-2921, Jul. 2015.
doi:10.1109/TAP.2015.2422838

6. Semkin, V., F. Ferrero, A. Bisognin, J. Ala-Laurinaho, C. Luxey, F. Devillers, and A. V. Raisanen, "Beam switching conformal antenna array for mm-wave communications," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 28-31, 2016.

7. Magalhaes, M. P., A. M. Engroff, L. S. Pereira, M. V. T. Heckler, and A. G. Girardi, "Synthesis of the radiation pattern of retrodirective antenna arrays using the particle swarm optimization algorithm," 2015 SBMO IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 1-5, Nov. 2015.

8. Saxena, P. and A. Kothari, "Ant lion optimization algorithm to control side lobe level and null depths in linear antenna arrays," AEU --- International Journal of Electronics and Communications, Vol. 70, No. 9, 1339-1349, 2016.
doi:10.1016/j.aeue.2016.07.008

9. Rahman, S. U., Q. Cao, M. M. Ahmed, and H. Khalil, "Analysis of linear antenna array for minimum side lobe level, half power beamwidth, and nulls control using PSO," Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. 16, 577-591, Apr. 2017.
doi:10.1590/2179-10742017v16i2913

10. Gao, Y., X. Jia, J. Xu, T. Long, and X.-G. Xia, "A novel DOA estimation method for closely spaced multiple sources with large power differences," 2015 IEEE Radar Conference (RadarCon), 1276-1279, May 2015.

11. Bartoli, G., R. Fantacci, D. Marabissi, and M. Pucci, "LTE-A femto-cell interference mitigation with music DOA estimation and null steering in an actual indoor environment," 2013 IEEE International Conference on Communications (ICC), 2707-2711, Jun. 2013.
doi:10.1109/ICC.2013.6654946

12. Yan, F., M. Jin, and X. Qiao, "Low-complexity doa estimation based on compressed music and its performance analysis," IEEE Transactions on Signal Processing, Vol. 61, No. 8, 1915-1930, Apr. 2013.
doi:10.1109/TSP.2013.2243442

13. Cui, K., W. Wu, J. Huang, X. Chen, and N.-C. Yuan, "2-D DOA estimation of LFM signals for uca based on time-frequency multiple invariance esprit," Progress In Electromagnetics Research M, Vol. 53, 153-165, 2017.
doi:10.2528/PIERM16112208

14. Lavate, T., V. Kokate, and A. M. Sapkal, "Performance analysis of music and esprit DOA estimation algorithms for adaptive array smart antenna in mobile communication," Second International Conference on Computer and Network Technology, 308-312, 2010.

15. Wu, Y., A. Leshem, J. R. Jensen, and G. Liao, "Joint pitch and DOA estimation using the esprit method," IEEE/ACM Transactions on Audio, Speech, and Language Processing, Vol. 23, No. 1, 32-45, Jan. 2015.
doi:10.1109/TASLP.2014.2367817

16. Hassoun, M., Fundamentals of Artificial Neural Networks, 1st Ed., MIT Press, Cambridge, Massachusetts, 2003.

17. Anthony, M., Neural Network Learning: Theoretical Foundations, 1st Ed., Cambridge University Press, Cambridge, United Kingdom, 2009.

18. Haykin, S., Neural Networks and Learning Machines, 3rd Ed., Pearson, London, United Kingdom, 2008.

19. Dorigo, M. and M. Birattari, Ant Colony Optimization, 36-39, Springer US, Boston, MA, 2010.

20. Zhang, X., S. Wang, L. Yi, H. Xue, S. Yang, and X. Xiong, "An integrated ant colony optimization algorithm to solve job allocating and tool scheduling problem," Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, Vol. 232, No. 1, 172-182, 2018.
doi:10.1177/0954405416636038

21. Sama, M., A. D'Ariano, D. Pacciarelli, P. Pellegrini, and J. Rodriguez, "Ant colony optimization for train routing selection: Operational vs tactical application," 2017 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS), 297-302, Jun. 2017.
doi:10.1109/MTITS.2017.8005684

Mr. Robert Macharia

Dr. Phillip Kibet Langat

Dr. Peter Kamita Kihato