Programmable LDPC decoder based on the bubble-sort algorithm

This paper presents a pipelined layered quasi-cyclic low-density parity-check (QC-LDPC) decoder architecture targeting low-complexity, high-throughput, and efficient use of hardware resources compliant with the specifications of 5G new radio (NR) wireless communication standard. First, a combined min-sum (CMS) decoding algorithm, which is a combination of the offset min-sum and the original min-sum algorithm, is proposed. Then, a low-complexity and high-throughput pipelined layered QC-LDPC decoder architecture for enhanced mobile broadband specifications in 5G NR wireless standards based on CMS algorithm with pipeline layered scheduling is presented. Enhanced versions of check node-based processor architectures are proposed to improve the complexity of the LDPC decoders. An efficient minimum-finder for the check node unit architecture that reduces the hardware required for the computation of the first two minima is introduced. Moreover, a low complexity a posteriori information update unit architecture, which only requires one adder array for their operations, is presented. The proposed architecture shows significant improvements in terms of area and throughput compared to other QC-LDPC decoder architectures available in the literature.

Download Full-text

Deep Learning-Based Object Detection, Localisation and Tracking for Smart Wheelchair Healthcare Mobility

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010091 ◽

2020 ◽

Vol 18 (1) ◽

pp. 91

Author(s):

Louis Lecrosnier ◽

Redouane Khemmar ◽

Nicolas Ragot ◽

Benoit Decoux ◽

Romain Rossi ◽

...

Keyword(s):

Object Detection ◽

Object Tracking ◽

Indoor Environment ◽

Distance Estimation ◽

Depth Estimation ◽

Detection Algorithm ◽

Use Case ◽

Detection Distance ◽

Detection Depth ◽

Sort Algorithm

This paper deals with the development of an Advanced Driver Assistance System (ADAS) for a smart electric wheelchair in order to improve the autonomy of disabled people. Our use case, built from a formal clinical study, is based on the detection, depth estimation, localization and tracking of objects in wheelchair’s indoor environment, namely: door and door handles. The aim of this work is to provide a perception layer to the wheelchair, enabling this way the detection of these keypoints in its immediate surrounding, and constructing of a short lifespan semantic map. Firstly, we present an adaptation of the YOLOv3 object detection algorithm to our use case. Then, we present our depth estimation approach using an Intel RealSense camera. Finally, as a third and last step of our approach, we present our 3D object tracking approach based on the SORT algorithm. In order to validate all the developments, we have carried out different experiments in a controlled indoor environment. Detection, distance estimation and object tracking are experimented using our own dataset, which includes doors and door handles.

Download Full-text

A novel error correction protocol for continuous variable quantum key distribution

Scientific Reports ◽

10.1038/s41598-021-90055-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kadir Gümüş ◽

Tobias A. Eriksson ◽

Masahiro Takeoka ◽

Mikio Fujiwara ◽

Masahide Sasaki ◽

...

Keyword(s):

Error Correction ◽

Quantum Key Distribution ◽

Ldpc Codes ◽

Key Distribution ◽

Continuous Variable ◽

Early Termination ◽

Parity Check ◽

Secret Key ◽

Ldpc Decoder ◽

And Performance

AbstractReconciliation is a key element of continuous-variable quantum key distribution (CV-QKD) protocols, affecting both the complexity and performance of the entire system. During the reconciliation protocol, error correction is typically performed using low-density parity-check (LDPC) codes with a single decoding attempt. In this paper, we propose a modification to a conventional reconciliation protocol used in four-state protocol CV-QKD systems called the multiple decoding attempts (MDA) protocol. MDA uses multiple decoding attempts with LDPC codes, each attempt having fewer decoding iteration than the conventional protocol. Between each decoding attempt we propose to reveal information bits, which effectively lowers the code rate. MDA is shown to outperform the conventional protocol in regards to the secret key rate (SKR). A 10% decrease in frame error rate and an 8.5% increase in SKR are reported in this paper. A simple early termination for the LDPC decoder is also proposed and implemented. With early termination, MDA has decoding complexity similar to the conventional protocol while having an improved SKR.

Download Full-text