data

1 Chapter 8: Angle Modulation Reception 2011

Introduction to Telecommunication(191210091)

Chris Roeloffzen

Chair: Telecommunication engineering (EWI)Floor 2 Carré building (CR2023)Telephone 489 2804E-mail: [email protected]


Today: Lecture 7

Chapter 8:

Angle Modulation Reception


Contents of the courseLecture 1 - 3: Introduction

Chapter 1: Introduction to Electronic CommunicationsChapter 2: Signal Analysis and Mixing

Lecture 4 - 7: CW modulationChapter 4: Amplitude modulation, TransmissionChapter 5: Amplitude modulation, ReceptionChapter 6: Single-side banded Communication SystemsChapter 7: Angle Modulation TransmissionChapter 8: Angle Modulation Receivers

Lecture 8 - 11: MediaChapter 12: Metallic Transmission LinesChapter 14: Electromagnetic Wave PropagationChapter 15: AntennasChapter 13: Optical Fibers

Lecture 12 - 14: Digital CommunicationChapter 9: Digital ModulationChapter 10: Digital Transmission

Lecture 15 & 16: ?????????????????For specific information see: www.el.utwente.nl/te/education/education.htm


Chapter 8:

Angle Modulation Reception


Chapter 8: Angle Modulation Reception

• Block diagram of FM receiver

• FM demodulators

• FM noise suppression

• FM thresholding

• FM capture effect

• FM stereo broadcasting


Double-conversion FM receiver block diagram

Fig 8-1


FM receiver block diagram

Fig 8-1


FM Demodulators: Slope detector

Fig 8-2



Slope Detector Envelope Detector

Fig 8-2

Fig 5-26



Disadvantage: Slope detector is also sensitive for amplitude variations

Fig 8-2

Fig 8-2b


FM Demodulators: Balanced Slope detector

Fig 8-2

Fig 8-2


FM Noise Suppression

Fig 8-9


Noise is greater than signal: Noise has captured the limiter

Signal is greater than noise: Signal has captured the limiter

FM thresholding, FM quieting, FM capture effect

FM thresholding

Fig 8-10


FM thresholding

Fig 8-11


FM capture effect

FM receivers have the ability to differentiate between two signals at the same frequency.

Suppression of the weaker signal is accomplished in amplitude limiters in the same manner that AM noise is suppressed.

Capture ratios of 1 dB are typical for high-quality FM receivers


FM Stereo broadcasting

SCA channel is only used in the US

Compatible with mono receivers

Fig 8-21


FM Stereo Transmitter

Fig 8-22


FM Stereo Receiver

Fig 8-25


FM Stereo matrix decoder

Fig 8-26


End Lecture 7


Next lecture: Chapter 12 Metallic cable transmission

Summary and Outlook

• Block diagram of FM receiver

• FM demodulators

• FM noise suppression

• FM thresholding

• FM capture effect

• FM stereo broadcasting

data

Documents

Transcript of data