Data Stream Processing Study in a Multichannel Telemetry Data Registering System

• Main Authors: I. M. Sidyakin, M. A. Elshafey
• Format: Article
• Language: Russian
• Published: MGTU im. N.È. Baumana 2015-01-01
• Series: Nauka i Obrazovanie
• Subjects: telemetry data; frame synchronization; synchronization code; the threshold of the synchronizer; Search mode; Verify mode; Lock mode; standard IRIG-106; symmetric binary channel with bit deletion; multi-channel registering system of TMI
• Online Access: http://technomag.edu.ru/jour/article/view/323

<p>The paper presents the results of research that is aimed to improve the reliability of transmission of telemetry information (TMI) through a communication channel with noise from the object of telemeasurements to the telemetry system for collecting and processing data. It considers the case where the quality of received information changes over time, due to movement of the object relative to the receiving station, or other factors that cause changes in the characteristics of noise in the channel, up to the total loss due to some temporary sites. To improve the reliability of transmission and ensure continuous communication with the object, it is proposed to use a multi-channel system to record the TMI. This system consists of several telemetry stations, which simultaneously register data stream transmitted from the telemetry object. The multichannel system generates a single stream of TMI for the user at the output. The stream comprises the most reliable pieces of information, being received at all inputs of the system.</p><p>The paper investigates the task of constructing a multi-channel registration scheme for telemetry information (TMI) to provide a simultaneous reception of the telemeasurement data by multiple telemetry stations and to form a single TMI stream containing the most reliable pieces of received data on the basis of quality analysis of information being received.</p><p>In a multichannel registering system of TMI there are three main factors affecting the quality of the output of a single stream of information: 1) quality of the method used for protecting against errors during transmission over the communication channel with noise; 2) efficiency of the synchronization process of telemetry frames in the received flow of information; 3) efficiency of the applied criteria to form a single output stream from multiple input streams coming from different stations in the discussed multichannel registering system of TMI.</p><p>In the paper, in practical implementation of the multi-channel registering system of TMI, additional effect obtained from applying a method of error-correcting coding TMI correcting omissions and inversion bits [1], is applied, as well as the effect of applying the criteria for the choice of parameters of TMI frame synchronizer [2]. This article presents the necessary and effective criteria for constructing the single output stream of information and to assess the quality of the output stream in various realizations of the multi-channel registering system of TMI.</p><p>The paper discusses two options for building a multi-channel recording system. The first variant of the system does not use additional methods of error-correcting coding during transmission. The second option for constructing a multi-channel system is based on the use of the developed combination of convolutional codes and low-density parity-check (LDPC) (error-correcting coding method presented in [1]).</p><p>The paper presents selection criteria of the most significant pieces of TMI input streams and a comparative analysis of the effectiveness of the proposed implementations. It gives a comparative assessment of the effectiveness of the proposed methods for constructing a multichannel recording system of TMI according to the following parameters: 1) bit error rate in the output TMI frame; 2) the percentage of fully reconstructed output frames; 3) the gain defined as the ratio of bit error rate in output TMI output frame for the systems under comparison.</p>