Diversity performance of dual antenna personal communication handsets

Short-term fading due to multipath propagation has a significant impact on personal wireless communication systems. Mitigating signal strength fluctuations due to interference between multiple replicas of the signal of interest arriving at the receiver over different paths is an active area of research. Antenna diversity is the technique where multiple antennas are used for transmission/reception to help overcome the effects of multipath fading. This paper gives a brief 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 (PIFA); back mounted PIFA with top mounted helix; top mounted PIFA and "flip" monopole. The indoor ISM band (902-928 MHz) propagation channel was of interest. The issue of data normalization is addressed and results showing its effect on the observed correlation are given. It is seen that the three proposed diversity systems yield sufficient decorrelation to warrant consideration for use in diversity systems.