Abstract
Content
- Introduction
- 1. Relevance of the topic
- 2. The purpose and objectives of the research, expected results
- 3. Brief overview of GSM-900 standard
- Conclusion
- References
Introduction
There is a necessary of the using of a mobile communication system for a person to carry out his activities in the modern world. So, nowadays, the remote exchange of information has the greatest importance in a person's life.
One of the main problems of the transferring information over a distance is to ensure the reliability of this information. This means that it is necessary to reduce the factors affecting the information transfer channel. Such factors include:
- Interference external influences (industrial noises, equipment noise, etc.);
- Interference associated with the implementation of the method of information transfer.
1. Relevance of the topic
Mobile networks are an integral part of the life of modern society for today. Technologies are being developed, and there is a growing need to protect the transmitted information over a wireless communication channel. This requirement includes protection against errors, which can further damage.
Improving noise immunity of mobile communication systems allows improving the parameters of the system. Using of these improvements allows to the systems to conform the basic modern requirements of society:
- Mobility of usage.
- Quality of transmission.
2. The purpose and objectives of the research, expected results
The main purpose of the work is researching of interference immunity of a mobile station of the GSM-900 standard, searching the solutions and methods of improving system performance.
Research plan:
- Analysis of the mobile communication GSM-900 standard.
- Analysis and evaluation of interference immunity of the system during transmitting information over a wireless communication channel.
- Model analysis using the LabView software.
Research object: GSM-900 mobile communication standard.
Research subject: methods of improving:
- the functioning of the system;
- the accuracy of the transmission of information;
- the characteristics of the system including the methods of interference protection.
As part of the master's thesis, it is planned obtaining the actual scientific results in the following areas:
- Development of improvements in the operation of mobile networks of the GSM-900 standard.
- Identification of the application areas of various options for the main stages of protection against interference in the transmission of information.
- Modeling processes to confirm the results of research.
3. Brief overview of GSM-900 standard
GSM (Global System for Mobile communications) – An open, digital cellular technology used for transmitting voice messages and data [1].
The GSM standard had become the first digital communication standard. It uses frequency and time division of channels. Each subscriber is assigned a certain frequency band for data exchanging between the subscriber's device and the base station. There is the time fixation of data transmission at the same time: the transmitter and the receiver work in half-duplex mode, but because of the use of high frequency transmission subscriber does not notice the interrupt data.
The mobile communication system based on the GSM standard is designed for their application in the commercial sphere. Such systems enable the user to obtain the following services:
- Transmission of voice messages and data, call signals and alarms.
- Connection to public telephone lines.
Digital methods that are used in mobile communications of the GSM standard, give the following advantages:
- Digital speech coding with lower speeds. Low-speed speech coding compatible with digital modulation techniques allows multiple voice channels to be transmitted on a single carrier, thereby increasing spectrum efficiency.– Digital speech coding with lower speeds. Low-speed speech coding compatible with digital modulation techniques allows multiple voice channels to be transmitted on a single carrier, thereby increasing spectrum efficiency.
- In comparison with analogue methods, digital modulation allows to increase the efficiency of using the frequency spectrum.
- The width of the frequency band is variable [2].
Table 1 [3, 5] presents the main characteristics of the GSM-900 standard.
| Table 1 | |
| Characteristics of the GSM-900 standard | Index |
| Frequencies of transmitting messages from the mobile station to the base station, MHz | 890 – 915 |
| Frequency of message transmission from base station to mobile, MHz | 935 – 960 |
| Duplex spacing of receive and transmit frequencies, MHz | 45 |
| Number of frequency communication channels with 1 communication channel width of 200 kHz | 124 |
| Bandwidth of the communication channel, kHz | 200 |
Conclusion
During the analysis of the GSM-900 mobile communication standard the basic principles of its operation and the features of the speech signals conversion were shown. Currently the topical issue is how to reduce the effect of electromagnetic noise on the quality of wireless communication. Research in this area will enhance knowledge in the field of interference-free stations, and will provide an opportunity to develop new methods of protection from interference as well as use them in future patent studies.
Taking into account that the work is at the development stage right now, presented materials can be slightly different from the text stated in the explanatory note. The full text of the work and all related materials can be obtained from the author or his supervisor since May 2018.
References
- Ассоциация GSMA (The GSM Association) [Электронный ресурс]. – Режим доступа: https://www.gsma.com/
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- GSM / Википедия [Электронный ресурс]. – Режим доступа: https://ru.wikipedia.org/wiki/GSM
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