Path Loss Models for LTE and LTE-A Relay Stations

Relaying technology is an essential part of 3GPP LTE-Advanced (3 Generation Partnership Project Long Term Evolution Advanced). This paper evaluates the path loss encountered on the backhaul link of relaying systems. The evaluation is based on an extensive measurements performed in 1900 MHz frequency band. The validity of different propagation models for multiple relay antenna heights is examined. The results of the analysis reveal that the applicability of commonly advocated models for relaying environment is still questionable. Some modifications of the original forms of the discussed models are introduced to make their predictions more reliable. With the proposed modifications, the analyzed models show good agreement with measurements. The prediction error is smaller than 0.37 dB, on average, and the accuracy ranges from 2.23 to 6.40 dB.