Outdoor-to-Indoor Propagation Loss Prediction in 800-MHz to 8-GHz Band for an Urban Area

In mobile communication systems, it is important to clarify the outdoor-to-indoor propagation loss (building penetration loss) characteristics to improve the quality of communication within buildings. This paper proposes a penetration loss prediction formula that is derived based on measurement results. We measured and analyzed the building penetration loss at higher frequencies that are appropriate for the next-generation system. We measured the propagation loss on 71 floors in 17 buildings in an urban area using four frequencies in the 800-MHz to 8-GHz band. The measurement results showed that the attenuation based on the penetration distance is 0.6 dB/m, the floor height gain is 0.6 dB/m, the constant value for the penetration loss is 10 dB, and there is no frequency dependence of the penetration loss in the frequency range from 0.8 to 8 GHz

Interference-Based Decode and Forward Scheme Using Relay Nodes in Heterogeneous Networks

This paper proposes interference-based decode and forward scheme that utilizes relay stations (RSs). In Long-Term-Evolution (LTE-) Advanced, heterogeneous networks in which femto- and picocells are overlaid onto macrocells are extensively discussed. However, interference between macro- and pico(femto)cells arises due to their different transmit power levels. Unlike conventional cooperative transmission schemes, the RS decodes interference in the first transmit timing period and forwards it to the user equipment (UE) in the second period. Moreover, cooperative transmission can be achieved without stopping the transmission from the base station (BS) to UE when forwarding the interference from the RS to the UE by utilizing the fact that signal-to-noise power ratio (SNR) between the RS and UE is much greater than that between the BS and UE. The basic performance of the proposed method is shown based on computer simulation. Moreover, the interference temperature and shadowing effect are measured when considering the coexistence between macro- and femtocells, and the performance of the proposed method is verified using measured shadowing effect