Analog Transmission with Analog Modulation

This chapter examines the need for modulation by studying the difference between baseband and broadband transmissions, and introduces the concept of annalog modulation, in which a carrier is always a sinusoidal signal and a message is always an analog signal. Modulation imposes changes in a message signal onto one of the parameters (amplitude, frequency, or phase) of the carrier wave. The chapter presents mathematical analysis of time-domain and frequency-domain presentations of angular (frequency and phase) modulation, and the practical aspects of amplitude, frequency, and phase modulations. Analog transmission is based on analog modulation; therefore, quality of analog transmission can be improved by using various techniques of analog modulation and demodulation.