Frequency Spectrum

HOMEWORK WEEK 2

CHAPTER 2

10. Frequency Spectrum- is a representation of all the frequencies and there amplitudes plotted in the frequency domain.

Bandwidth- a bandwidth of a frequency spectrum is the lowest subtracted from the highest frequency

11. Electrical Noise- any unwanted electrical energy the comes in with the pass-band for that signal

12. man-made- Man-made or industrial noise is noise created by mankind, for example spark-plugs, ac-power-generators.

Thermal- Thermal or white noise is the random and fast movement of electrons in a conductor.

Correlated noise- Nonlinear distortion that makes unwanted frequencies and degrades signals.

Impulse- Are sudden burst of irregularly shaped pluses that are very short.

16. Derived by Claude E. Shannon the Shannon limit for information capacity shows the signal to noise ratio for a given bandwidth. I=Blog_2(1+s/n) where I= information capacity(bps), B=bandwidth(hetz) and s/n=signal-to-noise ratio(unit less).

17. M-ary encoding the M represents the number of possible conditions for a given number of binary variables.

CHAPTER 5

1. Digital signals have many advantages over analog signals. Digital signals are immune to noise and can provide multiplexing. Digital transmission is a known bandwidth hog, and is incompatible with older analog systems.

2. PWM pulse width modulation , PAM pulse amplitude modulation, PPM pulse position modulation, PCM pulse code modulation.

5. Sample-and-hold circuit samples the analog input signal and converts those samples into a PAM.

8. Alias or fold-over-distortion occurs when f_s(minimum Nyquist sample rate(hertz) is less than two times f_a(maximum analog input frequency(hertz)

CHAPTER 6

3.T1 carrier systems are designed to combine PCM and TDM for transmission of 24 64-kbs channels with each channel capable of carrying digitally encoded data.

5. Used to indicate the silence periods between talk-spurts. Helps with trouble shooting voice issues (delayed speech) in PRIs.

CHAPTER13

3. Character codes, character sets, and symbol codes.

4. All characters do not have the same number of symbols or take the same amount of time to send.

7. Barcodes can allow for the organization of large