Diversity Performance of Multiantenna Systems for UMTS Cellular Phones in Different Propagation Environments

We present the evaluation of the diversity performance of several two-antenna systems for UMTS terminals. First, a two-antenna system with poor antenna-to-antenna isolation is described. Then, with the help of a neutralization technique, we introduced an optimized structure with high antenna-to-antenna isolation. The key parameters for an efficient diversity performance are then discussed, some of them being actually dependent on the propagation environment (uniform, indoor, outdoor, and outdoor-to-indoor chosen here). All these parameters, the total efficiency, the envelope correlation coefficient, the mean effective gain, the diversity gain, and the effective diversity gain, are computed with the help of the simulated radiation patterns of both antenna systems. Next, these key parameters are measured in a reverberation chamber to validate the simulations we achieved in the uniform environment. The comparison of the performance of the two prototypes is especially showing the usefulness of using a neutralization technique for enhanced diversity antenna systems.

[1]  Ross D. Murch,et al.  Compact integrated diversity antenna for wireless communications , 2001 .

[2]  Aliou Diallo,et al.  Enhanced two-antenna structures for universal mobile telecommunications system diversity terminals , 2008 .

[3]  Aliou Diallo,et al.  Reverberation chamber evaluation of multi-antenna handset having low mutual coupling and high efficiencies , 2006 .

[4]  C. Parini,et al.  Study of a dual-element PIFA array for MIMO terminals , 2006, 2006 IEEE Antennas and Propagation Society International Symposium.

[5]  Per-Simon Kildal,et al.  Diversity performance of a small terminal antenna for UMTS , 2003 .

[6]  M. B. Knudsen,et al.  Spherical outdoor to indoor power spectrum model at the mobile terminal , 2002, IEEE J. Sel. Areas Commun..

[7]  Claes Beckman,et al.  Evaluation of antenna diversity performance for mobile handsets using 3-D measurement data , 1999 .

[8]  Per-Simon Kildal,et al.  Correlation and capacity of MIMO systems and mutual coupling, radiation efficiency, and diversity gain of their antennas: simulations and measurements in a reverberation chamber , 2004, IEEE Communications Magazine.

[9]  Zhinong Ying,et al.  Two-antenna receive diversity performance in indoor environment , 2005 .

[10]  T. Taga,et al.  Analysis for mean effective gain of mobile antennas in land mobile radio environments , 1990 .

[11]  Zhinong Ying,et al.  Characterization of multi-channel antenna performance for mobile terminal by using near field and far field parameters , 2004 .

[12]  A. Diallo,et al.  Study and Reduction of the Mutual Coupling Between Two Mobile Phone PIFAs Operating in the DCS1800 and UMTS Bands , 2006, IEEE Transactions on Antennas and Propagation.

[13]  W. Ross Stone.  Handset Antennas for Mobile Communications: Integration, Diversity, and Performance , 1999 .

[14]  Joonho Byun,et al.  Definition of effective diversity gain and how to measure it in a reverberation chamber , 2002 .

[15]  Outi Kivekäs,et al.  Angular power distribution and mean effective gain of mobile antenna in different propagation environments , 2002, IEEE Trans. Veh. Technol..