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Initially designed for TV broadcasting, DVB standard families have become mature technologies for Internet communications via satellite access networks. A generic encapsulation protocol is therefore required for the forward link, the return link, and for mesh satellite systems. Moreover, because of the cost and the scarcity of resources, this should be as efficient and light as possible. The GSE (Generic...
In this paper, we evaluate a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for satellite broadcasting communications, where services with different quality of service (QoS) are desirable. A simple Land-Mobile-Satellite (LMS) channel model is presented, based on channel states and their transitions. The instantaneous channel capacity for suburban and forest scenarios is calculated...
This paper proposes a new 4-dimensional(4D) constellation-rotation(CR) method which obtains diversity gain of 4 under Rayleigh fading channels. The proposed scheme uses two consecutive CR operations for the constellation of QAM signals unlike a conventional 2-dimensional(2D) CR method using only one CR operation. The computer simulation results show that the new method outperforms the conventional...
In this paper, we focus on three different polynomial formats used in power amplifiers (PAs) pre-distortions. The nonlinearity of AM/AM and AM/PM introduced by power amplifiers are revealed by the transfer characteristics of PAs. We pick out the most effective polynomial format in evaluation of relative MSE (RMSE), the convergence speeds and the power spectral density (PSD). Such effective polynomial...
In this paper, a novel method called offset modulation (OM-OFDM) is proposed, to control the peak-to-average power ratio of an OFDM signal. The theoretical bandwidth occupancy of the proposed offset modulated signal is derived. Using this bandwidth occupancy a closed form theoretical bit error rate (BER) expression for an offset modulated transmission is further derived, validated and compared to...
This paper proposed an asymmetric QoS mapping mechanism in the handover between terrestrial and satellite networks which reduces handover blocking probability. This mechanism makes users in the terrestrial network degrade their requirements to access the satellite network with lower QoS class than they have in the terrestrial network when traditional one-one mapping fails. The users can recover their...
This paper summarizes some key features for future Chinese digital television terrestrial broadcasting (DTTB) systems including improved frame structure, transmit diversity, advanced channel coding and modulation, multi-service support, broadcasting return channel solution and etc.
The almost Gaussian nature of OFDM (Orthogonal Frequency Division Multiplexing) signals with high number of subcarriers is widely employed to characterize nonlinearly distorted OFDM signals and to evaluate the corresponding performance. In this paper we study the accuracy of the Gaussian approach when evaluating nonlinear effects in OFDM signals with finite number of subcarriers, showing the strengths...
We propose an improved CIR(Channel Impulse Response)-based fine STR(Symbol Timing Recovery) scheme for multi-input single-output (MISO) transmission mode of DVB-T2 system. At first, we present an efficient method to estimate the CIRs of MISO transmission. Then, the effective method for resolving the ambiguity of CIR is proposed by categorizing the ambiguity effect under the assumption of a false coarse...
This paper investigates the performance of time interleaving in DVB-T2 in the context of mobile reception. By means of time interleaving it is possible to provide time diversity and improve the robustness of the transmitted information in mobile environments. DVB-T2 implements a highly flexible time interleaving that allows different trade-offs in terms of time diversity, latency and power saving...
In this paper a number of low-complexity channel estimator structures tailored to the needs of LTE terminals have been investigated. The focus has been on the algorithms exhibiting reduced complexity while providing an acceptable level of performance. To design these estimators other factors such as interoperability with another OFDM-based standard, DVB-H, in a multi-standard environment have been...
Various terrestrial digital television broadcasting standards have been developed in the last two decades for both fixed residential and mobile receivers. Since personal mobile terminal integrated with multiple functionalities is becoming more popular, it is highly desirable to come up with a universal platform for mobile TV reception which can detect the system parameters of DTV signals automatically...
We previously proposed an iterative decision-directed channel estimation and inter-carrier interference (ICI) cancellation (IDD-ICICan) technique based on estimating the diagonal and off-diagonal vectors of the channel frequency response matrix (CFRM) of a double-selective fading channel. In this paper, we first present some new theoretical analysis that is missing from the previous investigation,...
A system that uses adaptive beamforming techniques for mobile DVB-S reception is proposed in this paper. The purpose is to enable DVB-S reception in moving vehicles. Phased arrays are able to electronically track the desired signal during dynamic behaviour of the vehicle the array is mounted on. The proposed system uses blind beamforming to adapt the array steering vector to changing signal (conditions...
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