Term
| What does transmitter do? |
|
Definition
|
|
Term
|
Definition
| demodulation and decoding |
|
|
Term
| what are three criteria in designing a digital communication system |
|
Definition
1. efficiency (power and BW)
2. reliability (error)
3. simplicity |
|
|
Term
| List 5 advantages of digital communication system |
|
Definition
1. all signals can be treated as same
2. accurate
3. easy to encrypt
4. easy to regenerate
5. |
|
|
Term
| List disadvantages of digital communication system |
|
Definition
1. more complex system
2. increased BW |
|
|
Term
| what is transfer function for a memory less channel? |
|
Definition
|
|
Term
|
Definition
| additive white Gaussian noise |
|
|
Term
| what is transfer function for channel with memory? |
|
Definition
| h(t) is not equal to delta(t) |
|
|
Term
|
Definition
| ISI is called inter symbol interference which is caused by band limited channel |
|
|
Term
|
Definition
| increase in probability of error at detection |
|
|
Term
| is creating memory less channel possible? |
|
Definition
| no because it requires delta function |
|
|
Term
|
Definition
when channel's BW is big compared to transmitted signal, then output of the channel will have transmitted signal that's slightly spreaded.
When channel's BW is small compared to transmitted signal, then output of the channel will have transmitted signal that's spreaded widely. |
|
|
Term
| How to design a system that will combat ISI? |
|
Definition
| make overall system like memory less |
|
|
Term
| What's the methodology used to design communication system? |
|
Definition
| Divide and Conquer - design w/o noise first, then add noise |
|
|
Term
| What are properties of white gaussian noise? |
|
Definition
1. the PSD is constant
2. for any t, PSD is a gaussian RV |
|
|
Term
| What's the equation for channel capacity? |
|
Definition
|
|
Term
| what is channel capacity? |
|
Definition
| rate of transferring bits without error |
|
|
