Chapter 3 Baseband pusle and Digital Signaling
1 Chapter 3 Baseband Pusle and Digital Signaling
Chapter Obiectives Analog-to-digital signa ling(PCM and delta modulation) Binary and multilevel digitals signals Spectra and bandwidths of digital signals Prevention of intersymbol interference Time division multiplexing Packet transmission
2 Chapter Objectives • Analog-to-digital signaling(PCM and delta modulation) • Binary and multilevel digitals signals • Spectra and bandwidths of digital signals • Prevention of intersymbol interference • Time division multiplexing • Packet transmission
3.1 Introduction(main goals) To study how analog waveforms can be converted to digital waveforms. The most popular technique is called PCM To learn how to compute the spectrum for digital signals To examine how to filtering of pulse signals affects out a bility to recover the digital information at the receiver(isn To study how we can multiplex data from several digital bit streams into on high-speed digital stream fro transmission over a digital system. TDM)
3 3.1 Introduction(main goals) • To study how analog waveforms can be converted to digital waveforms. The most popular technique is called PCM • To learn how to compute the spectrum for digital signals • To examine how to filtering of pulse signals affects out ability to recover the digital information at the receiver(ISI) • To study how we can multiplex data from several digital bit streams into on high-speed digital stream fro transmission over a digital system.(TDM)
3.2 Pulse Amplitude Modulation PAM is an engineering term that is used to describe the conversion of the analog signal to a pulse-type signal in which the amplitude of the pulse denotes the analog information The sampling theorem gives a way to reproduce an analog waveform by using sample values of that waveform and sin(x)z orthogonal functions PAM Signaling is to provide another waveform that looks like pulses yet contains the information that was present in tha analog waveforn
4 3.2 Pulse Amplitude Modulation • PAM is an engineering term that is used to describe the conversion of the analog signal to a pulse-type signal in which the amplitude of the pulse denotes the analog information • The sampling theorem gives a way to reproduce an analog waveform by using sample values of that waveform and sin(x)/x orthogonal functions • PAM signaling is to provide another waveform that looks like pulses ,yet contains the information that was present in tha analog waveform
3.2 Pulse Amplitude Modulation The pulse rate, fs, for PAM is the same as that required by the sampling theorem, namely, f s >=2B, where b is the highest frequency in the analog waveform and 2B is called the nyquist rate Classification Nature sampling(gating) Instantaneous sampling(Flat-top type)
5 3.2 Pulse Amplitude Modulation • The pulse rate, fs , for PAM is the same as that required by the sampling theorem, namely, fs>=2B, where B is the highest frequency in the analog waveform and 2B is called the Nyquist rate. • Classification : Nature sampling(gating) Instantaneous sampling(Flat-top type)