Estimation of P0 Multipath Occurrence Factor in Latvia

Abstract

As we know microwave transmission can be affected by deep fading, which can cause bit errors or even transmission loss. It happened when the Rx (receiving) signal is produced by a large number of components (vectors with random phases), then the Rx power level is variable with Rayleigh statistics. The Probability of having a fade depth A (dB) greater than a given depth A0 is (Rayleight formula) Pprob {A>A0}=P010-A 0 /10; P0- Multipath Occurrence factor. It is measure of multipath activity in radio hop. How to know P0? There are two possibilities: P0 can be estimated by monitoring the Rx Power and by processing measured data and P0 can be predicted by empirical propagation model. We had chosen first possibility. We collected data from twenty microwave hops during the year. As a result we practically find P0 value for Latvia, which can be taken into account during microwave hop planning and will let engineers to decrease microwave transmission interruption time. Ill. 2, bibl. 9 (in English, summaries in Lithuanian, English, Russian).