Constellation and Mapping Optimization of APSK Modulations used in DVB-S2 (original) (raw)
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BICMC and TD Comparative Performance Study of 16-APSK Signal Variants for DVB-S2 Systems
IEEE Communications Letters, 2015
A comparative performance study, in terms of Bit Interleaved Coded Modulation Capacity (BICMC) and Total Degradation (TD), between Amplitude Phase Shift Keying (APSK) signal variants for the 2nd generation Digital Video Broadcasting via Satellite (DVB-S2) system is presented. Motivated by the observation that the presence of more signal points in the outer ring of 16-APSK signals appears to improve the performance in a non-linear (NL) channel, we investigate the performance of 2-14 and 3-13 APSK signals with two novel bit-to-symbol mappings as alternatives to the 4-12 APSK, which is currently proposed as the modulation scheme for the DVB-S2 standard.
DVB-S2, the second generation standard for satellite broadcasting and unicasting
International Journal of Satellite Communications and Networking, 2004
DVB-S2 is the second-generation specification for satellite broad-band applications, developed by the Digital Video Broadcasting (DVB) Project in 2003. The system is structured as a toolkit to allow the implementation of the following satellite applications: TV and sound broadcasting, interactivity (i.e., Internet access), and professional services, such as TV contribution links and digital satellite news gathering. It has been specified around three concepts: best transmission performance approaching the Shannon limit, total flexibility, and reasonable receiver complexity. Channel coding and modulation are based on more recent developments by the scientific community: low density parity check codes are adopted, combined with QPSK, 8PSK, 16APSK, and 32APSK modulations for the system to work properly on the nonlinear satellite channel. The framing structure allows for maximum flexibility in a versatile system and also synchronization in worst case configurations (low signal-to-noise ratios). Adaptive coding and modulation, when used in one-to-one links, then allows optimization of the transmission parameters for each individual user, dependant on path conditions. Backward-compatible modes are also available, allowing existing DVB-S integrated receivers-decoders to continue working during the transitional period. The paper provides a tutorial overview of the DVB-S2 system, describing its main features and performance in various scenarios and applications.
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This article represents the results of a simulation study of the characteristics of a satellite television channel shaped under the DVB-S2 standard. The formulas for determining BER of a radio channel when using QPSK, 8QPSK and 16APSK modulation are produced. The algorithms determining the probability of error after LDPC and BCH decoders are represented. Based on the analysis of the characteristics of the DVB-S2 channel, its noise immunity is evaluated, as well as the permissible transmission rate of video information and the power efficiency of the system.
On 64-APSK constellation design optimization
2008 10th International Workshop on Signal Processing for Space Communications, 2008
This paper investigates the design of power and spectrally efficient coded modulations based on amplitude phase shift keying (APSK) with application to broadband satellite communications. Emphasis is put on 64APSK constellations. The APSK modulation has merits for digital transmission over nonlinear satellite channels due to its power and spectral efficiency combined with its inherent robustness against nonlinear distortion. This scheme has been adopted in the DVB-S2 Standard for satellite digital video broadcasting. Assuming an ideal rectangular transmission pulse, for which no nonlinear inter-symbol interference is present and perfect precompensation of the nonlinearity takes place, we optimize the 64APSK constellation design by employing an optimization criterion based on the mutual information. This method generates an optimum constellation for each operating SNR point, that is, for each spectral efficiency. Two separate cases of interest are particularly examined: (i) the equiprobable case, where all constellation points are equiprobable and (ii) the nonequiprobable case, where the constellation points on each ring are assumed to be equiprobable but the a priory symbol probability associated per ring is assumed different for each ring. Following the mutual information-based optimization approach in each case, detailed simulation results are obtained for the optimal 64APSK constellation settings as well as the achievable shaping gain.
1998
DVB-S2 is the second-generation specification for satellite broadcasting – developed by the DVB (Digital Video Broadcasting) Project in 2003. It benefits from more recent developments in channel coding (LDPC codes) combined with a variety of modulation formats (QPSK, 8PSK, 16APSK and 32APSK). When used for interactive applications, such as Internet navigation, it may implement Adaptive Coding & Modulation (ACM), thus optimizing the transmission parameters for each individual user, dependant on path conditions. Backwards-compatible modes are available, allowing existing DVB-S set-top-boxes to continue working during any transitional period.
DVB-S2 modem algorithms design and performance over typical satellite channels
International Journal of Satellite Communications and Networking, 2004
In this paper we propose a design of the main modulation and demodulation units of a modem compliant with the new DVB-S2 standard (Int. J. Satellite Commun. 2004; 22:249-268). A typical satellite channel model consistent with the targeted applications of the aforementioned standard is assumed. In particular, non-linear pre-compensation as well as synchronization techniques are described in detail and their performance assessed by means of analysis and computer simulations. The proposed algorithms are shown to provide a good trade-off between complexity and performance and they apply to both the broadcast and the unicast profiles, the latter allowing the exploitation of adaptive coding and modulation (ACM) (end-to-end system performances in term of BER versus the signal-to-noise ratio are shown as a result of extensive computer simulations. The whole communication chain is modelled in these simulations, including the BCH and LDPC coder, the modulator with the pre-distortion techniques, the satellite transponder model with its typical impairments, the downlink chain inclusive of the RF-front-end phase noise, the demodulator with the synchronization sub-system units and finally the LDPC and BCH decoders.
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The second generation of terrestrial digital video broadcasting standard (DVB-T2) offers several advantages for greater efficiency. Signal Space Diversity (SSD) contains rotated constellation and Q-Delay (RQD), which is one of advantage that offered to improve the performance over fading channels compared to the non-rotated modulation. In this journal, the proposed low-power de-mapper design of this work attempts to employ the introduced SSD to reduce power through replacing LLR calculations by a significantly less complex projectionbased de-mapping whenever possible. It benefits from an algorithm that applies projection-based de-mapping to significantly reduce LLR computations without deteriorating performance. Two versions are introduced for hard de-mapping and soft de-mapping. The design uses several techniques simultaneously to be even more energy efficient without affecting the performance. Prototype results indicate significant reduction of LLR calculations as Eb/N0 increases ...
Turbo-coded APSK modulations design for satellite broadband communications
International Journal of Satellite Communications and Networking, 2006
This paper investigates the design of power and spectrally efficient coded modulations based on Amplitude Phase Shift Keying (APSK) modulation with application to satellite broadband communications. APSK represents an attractive modulation format for digital transmission over nonlinear satellite channels due to its power and spectral efficiency combined with its inherent robustness against nonlinear distortion. For these reasons APSK has been very recently introduced in the new standard for satellite Digital Video Broadcasting named DVB-S2 [1]. Assuming an ideal rectangular transmission pulse, for which no nonlinear inter-symbol interference is present and perfect pre-compensation of the nonlinearity, we optimize the APSK constellation. In addition to the minimum distance criterion, we introduce a new optimization based on channel capacity; this new method generates an optimum constellation for each spectral efficiency. To achieve power efficiency jointly with low bit error rate (BER) floor we adopt a powerful binary serially concatenated turbo-code coupled with optimal APSK modulations through bit-interleaved coded modulation. We derive tight approximations on the maximumlikelihood decoding error probability, and results are compared with computer simulations. In Ref. [2], the current analysis is complemented with the effects related to satellite nonlinear distortion effects with a band-limited transmission pulse and including demodulator timing,