Evaluation of personal communications dual-antenna handset diversity performance

In personal wireless communications systems, multipath propagation has a significant effect on system design and performance. Signal strength fading caused by destructive interference between multiple replicas of the signal of interest arriving at the receiver over different paths often is the limiting factor in system range/fidelity. Antenna diversity is one technique that can be used to help overcome multipath fading. This paper presents a description of experiments, data processing, and results used to evaluate the diversity performance of three candidate dual-antenna handset configurations: two side-mounted planar-inverted F antennas (PIFAs), a back-mounted PIFA with a top-mounted helix, a top-mounted PIFA, and a "flip" monopole. In particular, the indoor industrial, scientific, and medical (ISM) band (902-928 MHz) propagation channel was of interest. These experiments did not include operator proximity effects, and in these tests, the dual-antenna handset remained stationary while the transmitter was moved along predetermined indoor paths. The issue of data normalization for extraction of fast fading behavior from measured data is addressed, with results showing its effect on observed correlation presented. Also, measured indoor fading distributions are presented and seen to fit the Rician and Rayleigh models well. From the diversity results presented, it is seen that the three proposed dual-antenna handsets yield sufficient decorrelation to warrant consideration for use in diversity systems.

[1]  Jonathan P. Castro.  Statistical Observations of Data Transmission Over Land Mobile Satellite Channels , 1992, IEEE J. Sel. Areas Commun..

[2]  Yoshihide Yamada,et al.  Base and Mobile Station Antennas for Land Mobile Radio Systems , 1991 .

[3]  R.G. Vaughan,et al.  Antenna diversity in mobile communications , 1987, IEEE Transactions on Vehicular Technology.

[4]  Rodney G. Vaughan,et al.  Polarization diversity in mobile communications , 1990 .

[5]  S. Seidel,et al.  914 MHz path loss prediction models for indoor wireless communications in multifloored buildings , 1992 .

[6]  J. D. Parsons,et al.  The Mobile Radio Propagation Channel , 1991 .

[7]  Donald C. Cox,et al.  Antenna Diversity Performance in Mitigating the Effects of Portable Radiotelephone Orientation and Multipath Propagation , 1983, IEEE Trans. Commun..

[8]  Kenneth K. Mei.  Time Domain Finite Difference Analysis of Antennas , 1990 .

[9]  J. Pierce,et al.  Multiple Diversity with Nonindependent Fading , 1960, Proceedings of the IRE.

[10]  Kenichi Kagoshima,et al.  Diversity antennas for base and mobile stations in land mobile communication systems , 1991 .

[11]  J. D. Parsons,et al.  Cross-correlation between 900 MHz signals received on vertically separated antennas in small-cell mobile radio systems , 1991 .

[12]  Yahya Rahmat-Samii,et al.  EM interaction of handset antennas and a human in personal communications , 1995, Proc. IEEE.

[13]  Mohamed El-Tanany,et al.  Experimental evaluation of space/frequency/polarization diversity in the indoor wireless channel , 1991 .

[14]  Patrick C. F. Eggers,et al.  Antenna Systems for Base Station Diversity in Urban Small and Micro Cells , 1993, IEEE J. Sel. Areas Commun..

[15]  J. P. Castro.  Data transmission over land mobile satellite channels , 1992 .

[16]  T.S. Rappaport,et al.  Radio-wave propagation for emerging wireless personal-communication systems , 1994, IEEE Antennas and Propagation Magazine.

[17]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[18]  William C. Y. Lee,et al.  Mobile Communications Engineering , 1982 .