A unified prediction method for space diversity improvement in received power on microwave links

Abstract

The space diversity technique is used widely to improve propagation impairment on line-of-sight microwave links. Although prediction methods for the space diversity improvement in received power were proposed the predicted results were quite different among all these methods.To investigate this point, a data bank was constructed. This data bank consists of 27 data from Japan, the United States, Italy, France, FRG, Sweden, and Finland. Some theoretical investigations also were conducted.Based on the investigations, it was clarified that the cause of the difference in predicted results was a regional dependence of the long-term variation in the short-term average of the received power. This regional dependence is included effectively in the Rayleigh fading Occurrence factor. A unified prediction method, which was derived by a multiple linear regression and included the Rayleigh fading Occurrence factor as a new parameter, was proposed. Based on the testing by the data bank, the proposed method was proved to be more accurate than the existing methods.