We show that the combined use of radio frequency absorbers and directive antennas can produce significant changes of the radio propagation channel properties along the positions of a virtual array inside a reverberation chamber. A multidimensional characterization of the channel was performed at 40 antenna positions with spacing of 0.233λ at 1 GHz. The average power, the Ricean K-factor, the coherence bandwidth, the r.m.s. delay spread, the mean delay, the beamforming power angle spectrum and array antenna correlation have been studied for different arrangements in the reverberation chamber. The analysis shows that the joint average over time and frequency channel behavior is, as expected, rather homogeneous along the very large array. However, individual realizations of the channel present a pronounced selective behavior in space, time and frequency with parameters varying along the positions of the virtual array suggesting that a heterogeneous behavior of the radio channels can be emulated in reverberation chambers. An important application of the presented study comprises testing of antenna array designs and algorithms in multipath environments. Further development may lead to Over The Air testing of Multiple Input Multiple Output antenna systems of various sizes, i.e., from small to very large arrays.
Andres Alayon Glazunov,
"Experimental Characterization of the Propagation Channel Along a Very Large Virtual Array in a Reverberation Chamber," Progress In Electromagnetics Research B,
Vol. 59, 205-217, 2014. doi:10.2528/PIERB14031203
2. Marzetta, T. L., "Non-cooperative cellular wireless with unlimited numbers of base station antennas," IEEE Trans. on Wireless Communications, Vol. 9, No. 11, 3590-3600, Nov. 2010. doi:10.1109/MSP.2011.2178495
3. Rusek, F., D. Persson, B. K. Lau, E. G. Larsson, T. L. Marzetta, O. Edfors, and F. Tufvesson, "Scaling up MIMO: Opportunities and challenges with very large arrays," IEEE Signal Processing Magazine, Vol. 30, No. 1, 40-60, Jan. 2013.
4. Liu, X. and M. E. Bialkowski, "Effect of antenna mutual coupling on MIMO channel estimation and capacity," International Journal of Antennas and Propagation, Vol. 2010, 306173-9, 2010, doi:10.1155/2010/306173.
5. Payami, S. and F. Tufvesson, "Channel measurements and analysis for very large array systems at 2.6 GHz," Proc. 6th European Conf. on Antennas and Propagation, EuCAP 2012, Prague, Czech Republic, Mar. 2012.
6. Gao, X., F. Tufvesson, O. Edfors, and F. Rusek, "Measured propagation characteristics for very-large MIMO at 2.6 GHz," Proc. 46th Annual Asilomar Conference on Signals, Systems and Computers, Nov. 2012.
7. Glazunov, A. A., V. M. Kolmonen, and T. A. Laitinen, "MIMO over-the-air testing," LTE-advanced and Next Generation Wireless Networks --- Channel Modelling and Propagation, Chapter 15, John Wiley & Sons, Oct. 2012.
8., 3GPP TS 34.114 V11.1.0, "User equipment (UE)/mobile station (MS) over the air (OTA) antenna performance," Conformance Testing (Release 11), Jun. 2012. doi:10.1109/TAP.2012.2201125
9. Kildal, P.-S., X. Chen, C. Orlenius, M. Franzen, and C. S. L. Patane, "Characterization of reverberation chambers for OTA measurements of wireless devices: Physical formulations of channel matrix and new uncertainty formula," IEEE Trans. Antennas Propagat., Vol. 60, No. 8, 3875-3891, Aug. 2012. doi:10.1109/TEMC.2012.2188896
10. Holloway, C. L., H. A. Shah, R. J. Pirkl, K. A. Remley, D. A. Hill, and J. Ladbury, "Early time behavior in reverberation chambers and its effect on the relationships between coherence bandwidth, chamber decay time, RMS delay spread, and the chamber buildup time ," IEEE Transactions on Electromagnetic Compatibility, Vol. 54, No. 4, 714-725, Aug. 2012. doi:10.1109/LAWP.2008.928488
11. Valenzuela-Valdes, J. F., A. M. Martinez-Gonzalez, and D. A. Sanchez-Hernandez, "Emulation of MIMO nonisotropic fading environments with reverberation chambers," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 325-328, 2008. doi:10.1109/TAP.2010.2096185
12. Sanchez-Heredia, J. D., J. F. Valenzuela-Valdes, A. M. Martinez-Gonzalez, and D. A. Sanchez-Hernandez, "Emulation of MIMO Rician-fading environments with mode-stirred reverberation chambers," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 2, 654-660, Feb. 2011. doi:10.1002/mop.1323
13. Rosengren, K. and P.-S. Kildal, "Study of distributions of modes and plane waves in reverberation chambers for characterization of antennas in multipath environment," Microwave Opt. Technol. Lett., Vol. 30, No. 20, 386-391, Sep. 2001. doi:10.1109/TAP.2006.883987
14. Holloway, C. L., D. A. Hill, J. M. Ladbury, P. Wilson, G. Koepke, and J. Coder, "On the use of reverberation chambers to simulate a controllable Rician radio environment for the testing of wireless devices," EEE Transactions on Antennas and Propagation, Vol. 54, No. 11, 3167-3177, Nov. 2006. doi:10.1049/el:20040411
15. Lienard, M. and P. Degauque, "Simulation of dual array multipath channels using mode-stirred reverberation chambers," Electronics Letters, Vol. 40, No. 10, 578-580, May 2004.
16. Kostas, J. G. and B. Boverie, "Statistical model for a mode-stirred chamber," IEEE Trans. Electromagn. Compat., Vol. 33, 366-370, Nov. 1991.
18. Garcia-Fernandez, M. A., J. D. Sanchez-Heredia, A. M. Martinez-Gonzalez, D. A. Sanchez-Hernandez, and J. F. Valenzuela-Valdes, "Advances in mode-stirred reverberation chambers for wireless communication performance evaluation," IEEE Communications Magazine, Vol. 49, No. 7, 140-147, Jul. 2011. doi:10.1109/MCOM.2004.1367562
19. Kildal, P.-S. and K. Rosengren, "Correlation and capacity of MIMO systems and mutual coupling, radiation efficiency, and diversity gain of their antennas: Simulations and measurements in a reverberation chamber," IEEE Communications Magazine, Vol. 42, No. 12, 104-112, Dec. 2004. doi:10.1049/el.2009.2489
20. Handel, P., S. Prasad, and C. Beckman, "Maximum likelihood estimation of reverberation chamber direct-to-scattered ratio," Electronics Letters, Vol. 45, No. 25, Dec. 2009.
21. Stoica, P. and R. Moses, Introduction to Spectral Analysis, Prentice-Hall, Englewood Cliffs, USA, 1997.