Description
ABSTRACT
The rapid evolution of radio communication systems and the high data rate demand for data transmissions require efficient modulation schemes in order to optimize the spectral efficiency of these systems.
This work is how to use digital signal processing to compensate for RF imperfections. We demonstrate that the strategy for developing transmitter to base on a total interaction between digital signal processing and pure radio concepts.
TABLE OF CONTENTS
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
TABLE OF CONTENT
CHAPTER ONE
- INTRODUCTION
1.1 BACKGROUND OF THE STUDY
1.2 PROBLEM STATEMENT
1.3 AIM / OBJECTIVE OF THE PROJECT
1.5 SCOPE OF THE PROJECT
1.5 SIGNIFICANCE OF THE PROJECT
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 OVERVIEW OF DIGITAL SIGNAL PROCESSING
2.2 COMPONENTS OF DIGITAL SIGNAL PROCESSING
2.3 ADVANTGES/FUNCTIONS OF DSP IN FM BROADCASTING
2.4 HISTORICAL BACKGROUND OF FM BROADCAST
2.5 REVIEW OF FM BROADCAST BANDS
2.6 MODULATION AND DEMODULATION
2.7 PRE-EMPHASIS AND DE-EMPHASIS
2.8 REVIEW OF MODULATION CHARACTERISTICS
CHAPTER THREE
3.0 METHODOLOGY
3.1 INTRODUCTION
3.2 BASICS OF FM BROADCATING TRANSMITTER
3.3 BLOCK DIAGRAM OF AN FM TRANSMITTER
3.4 FUNCTION OF FM TRANSMITTER BLOCK
3.5 APPLICATION OF DSP TECHNIQUES
CHAPTER FOUR
4.1 DIGITAL DELAY CORRECTION IN BROADCASTING TRANSMITTER
- CREST FACTOR REDUCTION
CHAPTER FIVE
5.0 CONCLUSION
5.1 RECOMMENDATION
5.2 REFERENCES
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Sound broadcasting as a wireless communications medium emerged in the 19th century. In the 1880s, the existence of radio waves was proven first theoretically, then experimentally. This was followed by rapid advancements. From the first radio broadcast transmitted in the US in 1906, it took only a few years until sound broadcasting had spread all over the world (Jong-Moon, 2017). Most radio listeners today receive frequency-modulated (FM) VHF radio. The technique of frequency modulation was developed in the 1920s; the first patents were filed between 1928 and 1934. Unlike amplitude modulation, which had been used almost exclusively until then, frequency modulation is insensitive to interference. Frequency-modulated signals in the VHF band offer excellent sound quality in a range perceptible by the human ear (Jong-Moon, 2017).
The great success of FM led to further enhancements of this technology. From the early 1960s, it was possible to receive stereo signals by encoding the left (L) and the right (R) channel into sum (L+R) and difference (L–R) signals. In the 1980s, Rohde&Schwarz played a key part in developing the radio data system (RDS), which was officially launched in 1987 and used mainly in car radios to provide alternative frequencies. RDS is in use even today, and in some countries it plays a significant role in providing traffic information (John, 2016).
Concurrently with the enhancement of FM, new sound and TV broadcasting standards emerged. In the 1990s, Rohde&Schwarz played a prominent role in the creation of the DAB broadcasting standard. Another new sound broadcasting standard was HD Radio, which was introduced in North America. This technology allows hybrid transmission of analog FM and digital HD Radio content.
FM receivers are used all over the world today due to their simplicity, high (sound) quality and low cost. FM technology is deployed today in large transmitter networks in every country in the world. Internet radio and portable media devices will complement, but not replace, the use of FM technology for sound broadcasting as a mass medium (John, 2016).
The main purpose of applying Digital Signal Processors (DSP) technology in FM radio transmitters is to take real-world signals audio and then mathematically manipulate them.
Signals from fm transmitters need to be processed so that the information that they contain can be displayed, analyzed, or converted to another type of signal that may be of use. In the real-world, analog transmitter detect signals such as sound and manipulate them. Converters such as an Analog-to-Digital converter then take the real-world signal and turn it into the digital format of 1’s and 0’s(John, 2016). From here, the DSP takes over by capturing the digitized information and processing it. It then feeds the digitized information back for use in the real world. It does this in one of two ways, either digitally or in an analog format by going through a Digital-to-Analog converter.
1.2 STATEMENT OF THE PROBLEM
Traditional fm transmitters were known by the quality of signals they broadcast which was said to be noisy and have no capacity to display their output digitally.
Traditional fm transmitters cannot cover large areas, and also Transmitting equipment of frequency modulation is complex.But the application of digital signal processing (DSP) techniques was introduced to overcome such problems by improving receivers performance, transmitting with lesser noise, now fm broadcasting have wider coverage and the modulation is simple.Digital signal processing (DSP) does all this work by converting the audio signal input into FM radio transmitter into digital signals 0 and 1, and processes it. The DSP takes over by capturing the digitized information and processing it. It then feeds the digitized information back for use in the real world.
1.3 AIM AND OBJECTIVES OF THE STUDY
The aim of this work is to carry out a study on enhancement of FM broadcasting system using Digital Signal Processing. The objectives of this study are:
- To enhance the performance of fm broadcasting
- To study the application of using Digital Signal Processing in FM broadcasting system.
- To study how broadcasting radio stations can provides high-quality audio broadcasting.
- To study factors that affect fm broadcasting
- To make a recommendation on how to improve fm broadcasting
1.4 SCOPE OF THE STUDY
The scope of this work covers how the development of a new FM broadcast system using digital signal processing (DSP) techniques will enhance the performance of an fm broadcasting system.
1.5 SIGNIFICANCE OF THE STUDY
This study will provide development of a new VHF/FM broadcast receiver using digital signal processing (DSP) techniques. The developed method gives improved receiver performance, and enables it to be integrated into general digital signal processing. This receiver realizes FM demodulation, a stereo decoder and noise reduction by using DSP.
- BENEFIT OF THE STUDY
- This study will serve as a means of studying the application of using Digital Signal Processing in FM broadcasting system.
- It will help the reader to factors that affect fm broadcasting
- The study will make the ready to become familiar with performance of fm broadcasting
CHAPTER FIVE
5.1 CONCLUSIONS
In this work we presented digital signal processing used to compensate for imperfections. We presented separately each DSP techniquefor enhancement of broadcasting transmitters performances. Obviously, allthese solutions have to be jointly optimized, eg. (Sperlich et al., 2014). Wehighlight that in addition to digital integration of transceiversolutions,adaptivealgorithms,whichenableunsupervised calibration, are the key to fulfill system requirements. It isinterestingtogofurtherbytacklingTXarchitectureasawhole,includingbothsignalprocessingandRFparts,andsee how far we can use signal processing concepts, as thoseemployed in receiver part, to improve both integration andperformances.
5.2 RECOMMENDATION
There are means of enhancing broadcasting transmitter performances, I recommend that those other method should be carried out in the future study.
