ELEC6255: wireless-communicatios: late add

Postgraduate/ELEC6255 IoT Networks/2020-10-22-wireless-communications.md

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+# Wireless Communications - The Physical Layer
+
+## A Digital Radio Communications System
+
+- Data
+- Source Encoder
+  - removes some data (for compression)
+  - _ADC_
+- Channel Encoder
+  - adds some data (for correction)
+- Modulator
+  - maps bits to symbols
+  - e.g. _GPSK, QAM, MSK_
+- Frequency Translation
+  - _900MHz, 2GHz, ..._
+- Amplifier
+  - adds power (_10W, 100W, ..._)
+- **Wireless Channel**
+- Low-noice Amplifier
+- Frequency Translation
+- Demodulator
+- Channel Decoder
+  - correct
+- Source Decoder
+  - decompress
+  - _DAC_
+- Data
+
+## Signals
+
+- Digital computations are done in discrete time
+  - **sampling** allows modern digital electronics to process, transmit, store and retrieve continuous-time signals
+
+## Sampling
+
+Refer to the slides:
+
+- Fourier Transform
+- Frequency Domain
+- Nyquist Rate and Aliasing
+  - https://en.wikipedia.org/wiki/Nyquist_frequency
+  - https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
+- Analogue-to-Digital Conversion
+- Digital-to-Analogue Conversion