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Digital Satellite Communications focuses on the study and design of efficient and flexible physical layers for broadband mobile and fixed satellite links. The chapters address long-term developments for advanced physical layer techniques in broadband communications, fixed and mobile terminals, and 4G evolutions with a potential convergence between different technologies. A general description of satellite systems and services is provided which organizes the material into a generalized and readable framework. The approach is both analytical and descriptive. The book provides a unified view of essential topics, including: - fundamental theories - channel coding and modulation - synchronization and parameter estimation - distortions and countermeasures - diversity techniques - multiplexing and multiple access schemes - software radio Digital Satellite Communications is ideal for researchers and students in the fields of communication and signal processing.

Digital Satellite Communications focuses on the study and design of efficient and flexible physical layers for broadband mobile and fixed satellite links. The chapters address long-term developments for advanced physical layer techniques in broadband communications, fixed and mobile terminals, and 4G evolutions with a potential convergence between different technologies. A general description of satellite systems and services is provided which organizes the material into a generalized and readable framework. The approach is both analytical and descriptive. The book provides a unified view of essential topics, including: - fundamental theories - channel coding and modulation - synchronization and parameter estimation - distortions and countermeasures - diversity techniques - multiplexing and multiple access schemes - software radio Digital Satellite Communications is ideal for researchers and students in the fields of communication and signal processing.

Digital Satellite Communications focuses on the study and design of efficient and flexible physical layers for broadband mobile and fixed satellite links. The chapters address long-term developments for advanced physical layer techniques in broadband communications, fixed and mobile terminals, and 4G evolutions with a potential convergence between different technologies. A general description of satellite systems and services is provided which organizes the material into a generalized and readable framework. The approach is both analytical and descriptive. The book provides a unified view of essential topics, including: - fundamental theories - channel coding and modulation - synchronization and parameter estimation - distortions and countermeasures - diversity techniques - multiplexing and multiple access schemes - software radio Digital Satellite Communications is ideal for researchers and students in the fields of communication and signal processing.

The successful DVB standard has now evolved into the DVB-S2 standard, which promises to bring very significant capacity gains. The main DVB-S2 feature is its adaptive air interface, where coding and modulation techniques are varied flexibly to maximize performance and coverage. This article addresses the design of the entire DVB-S2 communication chain, considering practical algorithms for coding, modulation, predistortion, carrier and SNR estimation, frame synchronization, and data recovery. The design complexity is exacerbated by the fact that DVB-S2 foresees 28 different coding/modulation pairs, demanding specific optimization and variable frame length. The performance achieved considering all possible impairments is compared to the ideal performance achievable in the Gaussian channel in terms of integral degradation, which ranges from 0.4 to 2,5 dB in going from QPSK to 32-APSK.

The authors deal with the sum-product algorithm (SPA) based on the hyperbolic tangent (tanh) rule when it is applied for decoding low-density parity-check (LDPC) codes. Motivated by the finding that, because of the large number of multiplications required by the algorithm, an overflow in the decoder may occur, two novel modifications of the tanh function (and its inverse) are proposed. By means of computer simulations, both methods are evaluated using random-based LDPC codes with binary phase shift keying (BPSK) signals transmitted over the additive white Gaussian noise (AWGN) channel. It is shown that the proposed modifications improve the bit error rate (BER) performance up to 1 dB with respect to the conventional SPA. These results have also shown that the error floor is removed at BER lower than 10 -6 . Furthermore, two novel approximations are presented to reduce the computational complexity of the tanh function (and its inverse), based on either a piecewise linear function or a quantisation table. It is shown that the proposed approximations can slightly improve the BER performance (up to 0.13 dB) in the former case, whereas small BER performance degradation is observed (

A system-level multi-standard simulator is set up to help the architectural and circuit-level design of RF front-ends whose building blocks are meant to be shared between transceiver chains of different standards. The simulator distinguishes the baseband digital processing and analog processing. Non idealities of analog blocks are modeled in detail taking into account the nonlinearities, band limitation, losses, thermal noise, etc. The simulator provides all classical compliance tests (sensitivity, maximum input, adjacent channel rejection, pureness of modulation, spectral profile, etc.) and can also assess the joint effect of high-level analog design parameters on the performance of the transmission chain at bit- or packet- level.