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ABSTRACT

Polarization diversity has already been considered for implementing a MIMO link in an indoor environment. However, the propagation characteristics play a leading role in the improvement of the channel performance. The objective of this paper is thus to study the possible application of this kind of diversity in a road or railway tunnel. Extensive measurement campaigns have been carried out in a straight arched tunnel and in a frequency band extending from 2.8 to 5 GHz. From the transfer functions between horizontally or vertically polarized elements of the transmitting and receiving virtual arrays, (4,4) MIMO matrices have been deduced. Different linear array architectures were studied, considering or not different polarizations within each array. Channel capacity was calculated assuming either a constant signal to noise ratio (SNR), whatever the array architecture, or a fixed transmitted power. Interpretation of the results is based on the correlation between elements and also on the variation of the SNR in the case of a fixed transmitted power

REFERENCES

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INDEX TERMS

Primary Classification:
  J. Computer Applications
  J.2 PHYSICAL SCIENCES AND ENGINEERING
      Subjects: Electronics

General Terms:
Measurement, Reliability

Keywords:
MIMO, diversity techniques, polarization, tunnel