Effect of path loss model on CDMA system design for highway microcells

Out-of-cell interference is an important factor in determining the system capacity of CDMA systems. Out-of-cell interference is influenced by propagation parameters such as slope index s of the path loss model, the standard deviation σ of shadow loss, and the correlation coefficients of shadow loss for propagation to the desired base station and to the interfering base station. For line-of-sight (LOS) cells along roadways, propagation may be described by a two slope model that has smaller slow fading loss σ and a larger slope index past the breakpoint R_b than the single slope model. As a result, smaller out-of-cell interference is obtained with the two slope model, leading to system designs having less infrastructure than are obtained using the single slope model