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In this paper, a propagation model is presented for the land mobile radio cellular systems with 3-D Gaussian distributed scatterers around Mobile Station (MS). The Base Station (BS) equipped with a directional antenna is located outside of the scattering region. The effect of directional antenna is thoroughly observed on spatial and temporal characteristics of the proposed model. General expressions...
This paper proposes a new concept in direct spectrum division transmission. The transmitter divides the single carrier modulated signal into multiple "sub-spectra" in the frequency domain and arranges each sub-spectrum so as to more fully utilize the unused frequency resources. In the receiver, the divided sub-spectra are combined in the frequency domain and demodulated. By editing the divided...
In this paper a novel optimal bit allocation for APSK modulation is proposed. Optimization is done by GA according to the satellite channel error sensitivity of the data. Furthermore, a new bit mapping is proposed for 16-APSK and 32-APSK. Results show the improvement of the proposed scheme with respect to the state of the art of the APSK modulation.
DVB-SH (Digital Video Broadcasting- Satellite Handled) is a broadcasting standard dedicated to hybrid broadcasting systems combining a satellite and a terrestrial part. On the satellite part, dedicated interleaving and time slicing mechanisms are proposed to mitigate the effects of Land Mobile Satellite (LMS) channel, based on a convolutional interleaver. Depending on the parameters of this interleaver,...
In this paper, we investigate the benefits of uniform circular arrays (UCAs) as an alternative antenna deployment to uniform linear arrays (ULA), which are commonly applied for multiple-input multiple-output (MIMO) systems. We consider a MIMO satellite link with focus on the Line-of-Sight (LOS) signal component of the MIMO channel between two geostationary satellites and a mobile earth terminal equipped...
Dimensioning the mobile link for aeronautical communications between aircraft and the satellite is a critical issue due to the limited power available, in particular if an omnidirectional antenna is used on board the aircraft. Also there are large channel variations due to the different effects occurring on the L-band mobile link and over-dimensioning of the user terminal or satellite should be avoided...
We propose a novel method that considerably reduces the Peak-to-Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) systems, yielding a quasi constant signal envelope in the time domain (PAPR close to 1 dB). The proposed technique, named Rotation Invariant Subcarrier Mapping (RISM), is a novel scheme for subcarriers data mapping, where the symbols belonging to the modulation...
A new upper bound is presented to the probability of error in detecting one out of M equiprobable signals in additive white Gaussian noise. This bound employs the same number of erfc function evaluations as the well-known Union Bound, but it is tighter. For high cardinality constellations, the Union Bound is useless for low signal-to-noise ratios being above 1, while the proposed new bound maintains...
In this paper, we derive an analytical model for the estimation of the overhead introduced in a file transfer procedure by three different reliable protocols, namely TCP, SCTP, and Saratoga. The model estimates the introduced overhead down to the IP layer, taking into account uncorrelated packet loss on the channel. The model distinguishes between the overhead on the forward link (server to client),...
In this paper, we examine different database synchronization/replication strategies and compare their suitability for satellite links in terms of latency and exchanged data volume. Earlier works have investigated the performance of these algorithms over terrestrial networks; however, the delay caused by a geostationary satellite has not been taken into account yet. A test-bed emulating a satellite...
This work presents an innovative, adaptive and optimal approach for Slotted-ALOHA protocols in Satellite Networks. Most ALOHA random access protocols are based on the assumptions that: i) all the involved stations receive packets with the same rate and ii) the transmission probabilities, computed analytically, are the same for each station. These assumptions are too optimistic, since, in real scenarios,...
We propose and analyze two strategies to provide different levels of quality of service (QoS) to the DVB-SH standard. An extension of the interleaving scheme is investigated to support low latency service requirements for interactive services based on short messages. The first approach is a straightforward extension of the DVB-SH interleaver scheme based on an early-uniform interleaver profile, and...
Networking has experienced tremendous changes. Once dedicated to one single type of services, technologies are now offering integrated services: we want to have access to any services anywhere. One challenge is the mobility, with 3G terrestrial offers beginning to be successful. In such a context, satellite systems appear as a real opportunity since they may fill the gap between dense connected areas...
The 2nd generation of Digital Video Broadcasting for Satellite (DVB-S2) standards allows the direct transmission of IP content using the Generic Stream Encapsulation (GSE) protocol, replacing the existing Transport Stream (MPEG-2 TS). This represents an evolution from the two current encapsulation methods: the native use of the Packetized Elementary Stream (PES) over TS for MPEG-2 encoded applications...
The current signalling framework for Digital Video Broadcasting (DVB) systems is based on MPEG-2 encoded Program Specific Information and System Information (PSI/SI) Tables that rely on the Transport Stream (TS). It is expected that in time, this architecture will be replaced by one based on the Generic Stream Encapsulation (GSE) protocol, paving the way for the convergence of DVB-S2 broadcast transmission...
Advanced communication and broadcasting systems use heavily diversity techniques to improve service availability. To analyze the performance of systems using techniques such as time diversity or time interleaving, antenna diversity and angle diversity, a detailed knowledge of the channel characteristics is essential. Especially the statistical analysis and the evaluation of the slow fading effect...
Sirius XM Radio, through its Sirius and XM Satellite Radio systems, broadcasts continuous high quality audio, video and data content to over nineteen million subscribers throughout the Continental United States (CONUS) and Canada. The original Sirius system utilizes three satellites in highly inclined orbits. The original XM system utilizes two satellites in geostationary orbits. Both systems achieve...
We consider a communication network with a single source node, a single destination node, and N intermediate nodes. We propose efficient techniques to increase the spectral efficiency of cooperative multihop transmission. We analyze the minimum total transmit power needed to achieve a desired end-to-end outage probability for a given rate for several schemes. In the first scheme, incremental relaying,...
This paper makes a survey of current trends and perspectives in the development of mobile satellite services in S-band in Europe. We present the recent evolutions and current status of different ongoing projects. We also identify current technology challenges and key drivers in the future evolution.
Digital Video Broadcasting - Satellite services to Handhelds (DVB-SH) and UMTS networks are located in very close portions of the electromagnetic spectrum and can thus operate in adjacent frequency bands. Consequently, an assessment of their coexistence is of primary importance. This paper presents an investigation into the reciprocal interference between the two systems. A method to characterize...
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