Implementation of Communication Systems
FEKT-MPC-IKSAcad. year: 2020/2021
The course is oriented to the real implementation problems of radio transmitters and receivers of single- and multi-carrier communication signals. Its emphasis is on both the theoretical description of basic algorithms for communication signals processing (sample rate change, filtration, synchronization, equalization, etc.), as well as on their practical software implementation with the use of available hardware (fixed-point arithmetic, analysis of signal transmitted from front-end, etc.). During the computer laboratories, students will get hands-on experience with the implementation of various transceiver algorithms on real signals of analog (e.g. FM radio) as well as digital (e.g. OFDM according WiFi IEEE 802.11a, FSK, QPSK/QAM) systems.
Learning outcomes of the course unit
The graduate of the course is able to: (a) convert the real numbers into fixed-point format and back; (b) create a program that implements the basic blocks of software defined transmitter with single and multiple carriers; (c) create a program able to demodulate QAM/QPSK/OFDM signal received using software defined receiver, including synchronization and simple channel equalization; (d) discuss the need and the solutions for sample rate change of signals incommunication transceivers; (e) explain the principle of CORDIC algorithm and its application in radio transceivers.
Student who register the course should be able to:
- compose a simple program in MATLAB environment
- synthesize simple FIR filter (low-pass, high-pass, raised cosine)
- mathematically describe signals of basic digital modulations (PSK, QAM, OFDM)
- discuss the basic terminology of signal processing
- discuss the advantages and disadvantages of basic communication technologies
Recommended optional programme components
Recommended or required reading
REED, J.H., Software Radio: A Modern Approach to Radio Engineering, Prentice Hall, 2002. (EN)
TRETTER, S.A., Communication System Design Using DSP Algorithms, Springer, 2008. (EN)
BEHROUZ, F. -B., Signal Processing Techniques for Software Radios, LuLu publishing, 2008. (EN)
Planned learning activities and teaching methods
Teaching methods include lectures and computer laboratories with the use of real communication signals captured by software defined transceivers
Assesment methods and criteria linked to learning outcomes
up to 30 points for computer lab in-class exercises (points are assigned for elaboration of practical assignments)
up to 70 points for exam (written 50 points + oral part 20 points)
The final exam consists of compulsory written and optional oral part. In order to procced for oral part, student has to get at least 20 points in the written part
Language of instruction
1. Architectures of transmitters and receivers, sub-band sampling, concept of software and software-defined radio.
2. Number representation, fixed-point arithmetic, CORDIC algorithm.
3. Hardware and software resources for implementation of communication systems.
4. Metrics to evaluate communication signals quality - EVM, ACPR, vector analysis.
5. Integer resampling - interpolation and decimation.
6. Fractional resampling, Farrow interpolator.
7. Digital filters and their effective FPGA implementation, FIR and CIC filters.
8. Basic building blocks of digital transceivers - DDS, mixers, methods of FM signal demodulation.
9. Algorithms for time and frequency synchronization of single-carrier and multi-carrier (OFDM) signals, carrier synchronization.
10. Equalization of communication signals.
11. Effective implementation of DFT - radix 2/4, DIT/DIF, mixed/split-radix FFT.
12. Parameters of real RF front-ends, IQ imbalance, amplifier nonlinearity, phase noise, software compensation techniques
13. QR decomposition and its application in communication systems, singular decomposition for MIMO systems.
The aim of the course is to get the students familiar with basic concepts and algorithms necessary for the implementation of modern radio transceivers, with the focus on their software implementation. The aim of the computer experiments is to gain practical experiences with the implementation of modulators and demodulators of single- and multi-carrier (OFDM) signals, including the implementation of symbol time synchronization and channel equalization algorithms.
Specification of controlled education, way of implementation and compensation for absences
Computer lab in-class excercises are compulsory.