CHAPTER 2 ANGLE AND PULSE MODULATION

2-1 CHAPTER 2 ANGLE AND PULSE MODULATION LEARNING OBJECTIVES Upon completion of this chapter you will be able to: 1. Describe frequency-shift keying (fsk) and methods of providing this type of modulation. 2. Describe the development of frequency modulation (fm) and methods of frequency modulating a carrier. 3. Discuss the development of phase modulation (pm) and methods of phase modulating a carrier. 4. Describe phase-shift keying (psk), its generation, and application. 5. Discuss the development and characteristics of pulse modulation. 6. Describe the operation of the spark gap and thyratron modulators. 7. Discuss the characteristics of a pulse train that may be varied to provide communications capability. 8. Describe pulse-amplitude modulation (pam) and generation. 9. Describe pulse-duration modulation (pdm) and generation. 10. Describe pulse-position modulation (ppm) and generation. 11. Describe pulse-frequency modulation (pfm) and generation. 12. Describe pulse-code modulation (pcm) and generation. INTRODUCTION In chapter 1 you learned that modulation of a carrier frequency was necessary to allow fast communications between two points. As the volume of transmissions increased, a need for more reliable methods of communication was realized. In this chapter you will study angle modulation and pulse modulation. These two types of modulation have been developed to overcome one of the main disadvantages of amplitude modulation - susceptibility to noise interference. In addition, a special application of pulse type modulation for ranging and detection equipment will be discussed.