Мобильная и беспроводная связь

В GSM используют +-45% поляризацию (x-pol): http://www.kathrein.pl/down/9985654.pdf
"By using multiple receiving antennas, more signal energy can be collected and therefore SNR can be improved when the signals from the antennas are coherently combined. Moreover, since these radio signals are independently faded, it is also possible to achieve divercity gain in th environment dominated by multipath propagation. The efficiency of antenna divercity, called divercity gain, depends on the grade of de-correlation between the diverscity receiving path. This gain can be achieved by deploying antennas with orthogonal polarization (X-pol) or by ensuring sufficient horizontal spatial separation between vertically polarized (V-pol) antennas. For example, for voice service, it can be assimed, that a two-branch receive divercity provides from 4 to 5 dB gain in the link budget...