Practical implementation of duobinary pulse position modulation using FPGA and visible light communication

Low bandwidth expansion modulation schemes are preferred for free space and optical fibre data transmission, where limited bandwidth is available. One such scheme is duobinary pulse position modulation (DuoPPM), which is the subject of this paper. DuoPPM scheme is not as sensitive to bandwidth expansion issues as digital PPM, with a line rate of twice the data rate. This paper discusses first time practical implementation of DuoPPM coding scheme and its application in free space using visible light LED (30 W) for transmission purposes. Experimental results achieved at the data rate of 14 Mbit/s indicate an error rate that is better than 1 error in 109.The main aim is to analyse the practicality, robustness and limitations of DuoPPM

Chrysalis Spring 1984

https://commons.lib.jmu.edu/chrysalis-1980s/1001/thumbnail.jp

Visible light communication based system using high power LED and dicode pulse position modulation technique

In this paper a dicode pulse position modulation (DiPPM) technique has been successfully implemented for an indoor visible light communication (VLC) based system using an FPGA and a commercial high power white LED (30W). A data rate of 13 Mbps has been achieved with a bit error rate (BER) <10-11 at a free space distance of 1.2 m through a basic transceiver circuit, and 14.5 Mbps with 1.15x10-6 of BER. Furthermore, a data rate of 13 Mbps has been successfully transmitted over a distance of 1.8 m with BER of 10-5. This proves that the application of DiPPM is a viable modulation system over free space communication links

New Avenues for Automated Railway Safety Information Processing in Enterprise Architecture: An NLP Approach

Enterprise Architecture (EA) is crucial in any organisation as it defines the basic building blocks of a business. It is typically presented as a set of documents that help all departments understand the business model. In EA, safety documents are used to manage and understand safety risks. A novel similarity system for railway safety document processing is presented in this work. It measures the feasibility of automated updating of EA models with the Rule Book by verifying whether Rail Safety and Standards Board (RSSB&#x2019;s) Rule Book clauses are present and complete in existing EA models. Additionally, a Natural Language Processing (NLP) based search feature was developed to drill through the database to find similar existing rules, principles, and clauses based on semantic similarity. The result will display the most similar clauses and rules with similarity scores and document names. In this study, different pre-trained Electra Small, DistilBERT (Distillation Bidirectional Encoder Representations from Transformers) Base and BERT (Bidirectional Encoder Representations from Transformers) Base were used to embed text. Additionally, the similarity between document rules was measured by cosine similarity metrics. With conclusive evidence, our findings show that BERT Base exceeds the other embedding methods in the semantic comparison of documents