Fig 6 - uploaded by M. Tomlinson
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Single user (16-QAM and QPSK performance) versus two user (QPSK) performance. Results use either a symbol or bit interleaver as labelled. The average number of iterations performed are shown for the single user 16QAM BER curves.
Source publication
This paper investigates the design and performance of a two-user satellite communication system. Each user is independently encoded using a structured Turbo code with identical symbol interleavers. This permits Turbo decoding to be performed using the combined component code trellises, which provides significant gains over independent decoding. The...
Contexts in source publication
Context 1
... found that the interleaver design was more difficult for the single user 16-QAM case. In order to maintain good con- vergence we had to perform symbol decoding with interleaver symbol size equal to the modulation symbol size (in this case, 4 bits). This requirement is illustrated in Fig. 6, where the single user 16-QAM system with a symbol based interleaver outperforms that with a bit based interleaver in terms of FER. This is in spite of the fact that the minimum distance of the Turbo code with the bit interleaver is d min = 51 as opposed to d min = 32 when using the symbol interleaver. In addition, the symbol ...
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... outperforms that with a bit based interleaver in terms of FER. This is in spite of the fact that the minimum distance of the Turbo code with the bit interleaver is d min = 51 as opposed to d min = 32 when using the symbol interleaver. In addition, the symbol interleaver case requires fewer iterations on average at a given BER/ FER as shown in Fig. 6. This shows the importance of using symbol decoding for Turbo codes with higher order modulation (also mentioned in [16]). However, this requirement reduces the interleaver design freedom. Over- all the 4-bit symbol interleaver has size 500 symbols (2000 bits) and S = 12 (after swaps). While the bit interleaver has size 2000 bits and S ...
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... order to obtain good error floor performance we use a memory 5 component code with ff = 45 (octal) and fb = 67 (octal). The performance is compared to the two user performance in Fig. 6. As can be seen, the two user performance is only 0.2 dB away from the single user 16- QAM (symbol interleaver) performance at a FER of 10 −2 . The single user QPSK performance is also shown in Fig. 6. It provides the best performance, but only transmits k = 1000 data bits over N = 1500 symbol ...
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... performance we use a memory 5 component code with ff = 45 (octal) and fb = 67 (octal). The performance is compared to the two user performance in Fig. 6. As can be seen, the two user performance is only 0.2 dB away from the single user 16- QAM (symbol interleaver) performance at a FER of 10 −2 . The single user QPSK performance is also shown in Fig. 6. It provides the best performance, but only transmits k = 1000 data bits over N = 1500 symbol ...
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Citations
... Results shown in [44] evidence that turbo-TCM may improve system robustness both in presence of Rayleigh fading and non-linear distortion. Turbo coding is also considered in [45] for shared satellite channels with collisions. In this framework, it is worth mentioning the work of Howard and Schlegel [46], where a novel approach for turbo-coded differential modulation. ...
... EHF frequency bands, such as the Ka-Band (20-30 GHz), Q-V band (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50) and W band offer the bandwidth to support future broadband satellite networking. High capacity EHF satellite communication systems may someday support data rates from 100s of Mbps to Gbps; similar to short range terrestrial wireless systems. ...
The exploitation of extremely high-frequency (EHF) bands (30-300 GHz) for broadband transmission over satellite links is currently a hot research topic. In particular, the Q-V band (30-50 GHz) and W-band (75-110 GHz) seem to offer very promising perspectives. This paper aims at presenting an overview of the current status of research and technology in EHF satellite communications and taking a look at future perspectives in terms of applications and services. Challenges and open issues are adequately considered together with some viable solutions and future developments. The proposed analysis highlighted the need for a reliable propagation model based on experimental data acquired in orbit. Other critical aspects should be faced at the PHY-layer level in order to manage the tradeoff between power efficiency, spectral effi- ciency, and robustness against link distortions. As far as net- working aspects are concerned, the large bandwidth availability should be converted into increased throughput by means of suitable radio resource management and transport protocols, able to support very high data rates in long-range aerospace scenarios.
