Digital modulation techniques
- 2. INTRODUCTION • WHAT IS MODULATION: In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. .Digital modulation uses discrete signals for modulating a carrier wave i.e if a binary signal modulates a high frequency carrier signal then it is called as “Digital modulation”
- 3. Types of digital modulation • There are several kinds of digital modulation techniques are available based on the requirement which includes the following. • ASK or Amplitude shift Key • FSK or Frequency shift key • PSK or Phase shift key
- 8. Synchronous and Asynchronous detection • Generally there are two types of Demodulation techniques. They are 1.Asynchronous Demodulation/detection 2.Synchronous Demodulation/detection • The clock frequency at the transmitter when matches with the clock frequency at the receiver, it is known as a Synchronous method, as the frequency gets synchronized. Otherwise, it is known as Asynchronous.
- 9. Amplitude-shift keying (ASK) • Amplitude-shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave. In an ASK system, the binary symbol 1 is represented by transmitting a fixed-amplitude carrier wave and fixed frequency for a bit duration of T seconds. If the signal value is 1 then the carrier signal will be transmitted; otherwise, a signal value of 0 will be transmitted.