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Publications associées (89)

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Mobile network operators constantly have to upgrade their cellular network to satisfy the public's hunger for increasing data capacity. However, regulatory limits regarding allowed electromagnetic field strength on existing cell sites often limit or prevent the installation of new cells on additional frequency bands. Further densifying the radio access infrastructure by means of new cell sites takes time because of the site acquisition, the need for permissions, and the civil construction. To this end, amplify-and-forward repeaters are a cost-efficient method to provide mobile wireless data capacity to concealed areas outdoors, inside buildings, or vehicles, where low signal levels drastically limit the achievable capacity or even prevent communication with distant base stations. Repeaters with high-gain beamforming antennas can be used to decrease the path loss and thereby offer a higher capacity than user equipment otherwise could achieve. Since those highly directional beams must be constantly adjusted, we propose methods to align and track the beam even without having access to in-band beam control mechanisms. Numerical analyses with measurement data show that such non-invasive (system data-agnostic) methods are feasible and only incur a few percent in throughput reduction.

IEEE2022

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ErgoDEC: A Fault Tolerant 28 nm LDPC Decoder Providing Stable FER Quality with Unreliable Memories

Andrea Bonetti, Andreas Peter Burg, Reza Ghanaatian Jahromi, Robert Giterman

Communication systems have been associated with an inherent fault tolerance to hardware reliability issues. Therefore, many publications have studied the impact of such issues on, for example, channel (mostly LDPC) decoders. Since all of these studies are so far only based on simulations, we implement an LDPC decoder in a 28nm technology, specifically to verify the corresponding assumptions and quality metrics. Our measurements indicate a large quality spread across a population of dies, which is not visible when considering an average quality across simulation runs with random fault injection. Such a quality spread is detrimental since in high-volume manufacturing a certain minimum quality must be guaranteed for all accepted dies. The latter is only possible with an ergodic behaviour in which the quality of any faulty die is indicative for the quality of all dies in the population. To alleviate this issue, ErgoDEC provides simple architectural measure to restore an ergodic behaviour in the presence of memory reliability issues. This more stable quality can also be observed in our measurements and can be exploited to further improve the resilience against faulty bits.

2022

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Ultra-High-Throughput EMS NB-LDPC Decoder with Full-Parallel Node Processing

Hassan Harb

This paper presents an ultra-high-throughput decoder architecture for NB-LDPC codes based on the Hybrid Extended Min-Sum algorithm. We introduce a new processing block that updates a check node and its associated variable nodes in a fully pipelined way, thus allowing the decoder to process one row of the parity check matrix per clock cycle. The work specifically focuses on a rate 5/6 code of size (N, K) = (144, 120) symbols over GF(64). The synthesis results on a 28-nm technology show that for a 0.789 M NAND-gates complexity complexity, the architecture reaches a decoding throughput of 0.9 Gbps with 30 decoding iterations. Compared to the 5G binary LDPC code of the same size and code rate, the proposed architecture offers a gain of 0.3 dB at a Frame Error Rate of 10(-3).

SPRINGER2022

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