Adapting DVB-SH system parameters to mobile environments

Abstract

A performance analysis of the digital video broadcasting - satellite to handheld (DVB-SH) system in presence of ground mobile terminals (GMTs) is presented. The paper focuses on the Doppler spread issue. Indeed, the mobility of GMTs induces a Doppler spread in the orthogonal frequency division multiplexing (OFDM) signal that destroys the orthogonality of subcarriers. The loss of orthogonality produces inter-carrier interference (ICI) and hence a degradation of the system performance in terms of symbol error probability. The paper presents the conditions in which this degradation can be compensated for by an increase in the signal to noise ratio (SNR) at the receiver side. The result depends on both the modulation scheme and the speed of GMTs. Inversely, having a maximum allowable margin on the received SNR allows us to determine an upper bound on the mobile station velocity.