SFN channel measurements in Brazil

Maurício V Guerra,Luiz Da Silva Mello,Carlos V Rodriguez R

doi:10.1590/s2179-10742013000100006

Abstract

In this paper, field measurements carried out in a suburban SFN network with two synchronized transmitters are reported. It is found that the radio signal coverage of the distributed transmission scheme is distinctly improved when compared to a single transmitter system. The path loss gain and improvement associated to the SFN scheme are obtained as well as the multipath channel parameters including the mean and RMS delay spread. A tapped delay line is used to model the average power delay profile (PDP) in the distributed transmission cases and shows rather different features than the single transmission case.

Highlights

In a DTV traditional wireless transmission scenario, only one transmitter is used to transmit the wanted signal in an assigned channel to a given user
The signal strength variation is characterized by the path loss, as given by [1,2], and the time delay dispersion of received signal, expressed by power delay profile (PDP) [3], that is usually modeled by an exponential decay
The path loss gain and improvement associated to the Single Frequency Network (SFN) scheme are obtained, as well as the multipath channel parameters, including the mean delay and root mean square (RMS) delay spread

Summary

INTRODUCTION

In a DTV traditional wireless transmission scenario, only one transmitter is used to transmit the wanted signal in an assigned channel to a given user. Signals from other transmitters are taken as interferences and should be kept out of the assigned frequency or time or coding channel of the given user In such case, the signal strength variation is characterized by the path loss, as given by [1,2], and the time delay dispersion of received signal, expressed by power delay profile (PDP) [3], that is usually modeled by an exponential decay. The channel characteristics for SFN transmission differ from the traditional single transmitter case due to the presence of signals reaching the receiver originating from more than one transmitter These signals create a severe artificial multipath propagation environment at the receiver as observed by Tang et al.[5], Zhao et al [6] and Guerra et al.[7]. A tapped delay line is used to model the average power delay profile (PDP) in the distributed transmission cases and shows rather different features than the single transmission case

EXPERIMENTAL SETUP

WIDEBAND CHANNEL CHARACTERIZATION

Findings

CONCLUSIONS