Sampling Sampling provides a discrete-time representation of a continuous waveform Sample points are real-valued numbers In order to transmit over a digital system we must first convert into discrete valued numbers
Sampling Given a continuous time waveform, can we represent it using discrete samples? How often should we sample? Can we reproduce the original waveform?
Automatic repeat request (ARQ) Break large files into packets FILE PKT PKT PKT Check received packets for errors Use a feedback channel to request retransmissions Retransmit packets containing errors acket Receive ACK
The signal suffers an attenuation loss l Received power PR= PT/L Received snr=E,/No, Eb=Pr/Rb Antennas are used to compensate for attenuation loss Capture as much of the signal as possible
