Variable rate multicarrier schemes over integrated Satellite-terrestrial system

In this paper, we propose the use of OFDM-CDMA based transmission schemes to support Variable Bit Rate (VBR) services at the physical layer of Digital Video Broadcast Satellite Handheld (DVB-SH)-A architecture. For this purpose, multicarrier schemes namely Spread Orthogonal Frequency Division Multiplexing (SOFDM), Complementary Code Keying (CCK-OFDM) and conventional OFDM are analyzed over integrated satellite-terrestrial system, employing 3-state Fontan Land Mobile Satellite (LMS), and TU6 and RA6 terrestrial channel models. Variable rates are assumed for SOFDM and CCK-OFDM. The VBR multicarrier performance analysis over the employed integrated system would be helpful in investigating the 5G communication scenario in future. At the receiver, linear Minimum Mean Squared Error (MMSE) equalizer is applied for the considered multicarrier schemes. The BER performance results illustrate that SOFDM outperforms OFDM, and CCK-OFDM for all the considered data rates, in both the Land Mobile Satellite (LMS) and terrestrial channel conditions. Later, the block-by-block system computational complexity of the multicarrier schemes is evaluated. It is shown that the complexity of SOFDM system is rate-dependent as compared to the fixed complexity CCK-OFDM system. Hence, a trade-off exists between the achieved error performance and system complexity. Therefore, for high data rate transmission SOFDM scheme could be a suitable candidate for integrated satellite-terrestrial communication system, or 5G satellite system in future.