2.4. Conclusion
We have shown that throughputs towards 1 Tbit/s are feasible for all three code classes by appropriate “unrolling”, using heavy pipelining and spatial parallelism. However, this architectural approach is limited to small block sizes and small numbers of iterations (Turbo and LDPC codes), which negatively impacts the communications performance. Moreover, although pipelining largely increases the throughput and locality, it also increases the latency. All architectures suffer from limited flexibility in terms of block sizes (all three codes), varying number of iterations (Turbo and LDPC codes) and code rate flexibility (LDPC and Polar codes). In summary, the biggest challenge for very high-throughput decoder architectures lies in the improvement of the communications performance, under the aforementioned implementation constraints and providing block size, code rate and algorithmic flexibility. As discussed in the introduction, microelectronic progress will largely contribute to an improved area efficiency but not as much to an increased performance and a reduced power density. Thus, further research is mandatory to keep pace with the increasing requirements on communication systems in terms of throughput, latency, power/energy efficiency, flexibility, cost and communications performance.
2.5. Acknowledgments
We gratefully acknowledge financial support by the EU (project-ID: 760150-EPIC).
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1 For a color version of all figures in this book, see www.iste.co.uk/andrade/multi2.zip.
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