This subject gives students a knowledge of the main processes involved in a digital transmission communications system and the know-how to design simple communications circuit blocks.
Introduction to digital communication processes
Basic model of physical layer communications. Review of dB, dBm and SNR examples in communications engineering. Time domain and frequency domain concepts. Review of amplitude and frequency modulation. Review of complex number formats used in this module. Introduction to concepts in phase modulation. Introduction to concept of eye diagram. Probability of error, bit error rate, Eb/No graphs. Bandwidth and spectral efficiency.
Information theory and Source Coding
Information measure, Discrete memoryless source , entropy, information rate.Source coding, Shannon-Fano, Huffman, coding efficiency; Shannon's channel capacity theorem.
Channel Coding
Binary symmetric channel, redundancy and error detecting/correcting codes; block codes, linear block codes, Noise words, Hamming distance,minimum Hamming distance vs. error detection/correction capability, paritycheck matrix, syndromes and error detection and correction,circuit implementation of a simple Hamming code. Data interleaving - application to LTE(4G).
Sampling and Pulse Code Modulation (PCM)
Sampling theorem (Nyquist theorem), types of sampling, spectrum of sampledsignal, aliasing. quantisation and quantisation noise, signal-to-quantisation noiseratio and coding schemes, PCM. Codec Standards.PCM multiplexing, PCM E1 frame, European Synchronous Digital Hierarchy(SDH). SDH Frame Structure (STM-1). Synchronous Optical Network (SONET) data rates.
Baseband techniques
Minimum bandwidth required to transmit digital signals at a certain bit rate.(Nyquist transmission theorem). Timing Recovery. Effect of impairments on baseband binarysignals. ISI, jitter, the eye pattern, raised cosine filters, equalisation, noise margin, thresholddetection. Line coding: Non return to zero and return to zero signals; alternatemark inversion, Manchester code, Clock recovery.
Bandpass transmission
The radio spectrum. Radio channels. Simple channel model. Fading. Reflections and multi path considerations. Overview of up-conversion process, spectral analysis of a mixer. BPSK transmitter and receiver, Bandwidth consideration ofBPSK, carrier recovery, clock recovery. I-Q diagram. QPSK transmitter and receiver; truthtable, I-Q constellation diagrams, bandwidth consideration ofQPSK. Phase coherence. QAM transmitter and receiver block diagrams, bandwidth considerations, constellation patterns. Higher order modulation examples. Introduction to OFDM; symbol rate vs. channel separation.
| Module Content & Assessment | |
|---|---|
| Assessment Breakdown | % |
| Other Assessment(s) | 30 |
| Formal Examination | 70 |