Communication Systems
Every scheme in this subject is a different answer to the same question: how do you get a signal across a channel that distorts it, shares it and adds noise to it? These topics animate the spectrum, not just the waveform.
Start from the beginning →1 topic you can watch now, 25 still to come.
Foundations
The block diagram, and why the hard part is in the middle.
- Elements of a communication system
- Baseband vs passband
- Bandwidth and the channel
- Noise, SNR and the noise figure
Amplitude modulation
Put the message in the size of the carrier.
- AM: spectrum, power and efficiency
- Modulation index and overmodulation
- DSB-SC, SSB and VSB
- Envelope and coherent detection
- Superheterodyne receiver
Angle modulation
Put the message in the frequency instead, and buy noise immunity.
- FM and PM
- Narrowband and wideband FM
- Carson's rule
- FM demodulation and pre-emphasis
Pulse and digital modulation
Sample it, number it, and send the numbers.
- PAM, PWM and PPM
- PCM, quantisation noise and companding
- Delta modulation
- ASK, FSK, PSK and QAM
- Matched filter and bit error rate
Multiplexing and access
One channel, many users, without them destroying each other.
- FDM and TDM
- TDMA, FDMA and CDMA
- Spread spectrum
Information theory
The limits no clever engineering can get past.
- Entropy and information rate
- Source coding: Huffman and Shannon-Fano
- Channel capacity and the Shannon-Hartley theorem
- Error-detecting and correcting codes