Unit name | Advanced Mobile Radio Techniques |
---|---|

Unit code | EENGM2510 |

Credit points | 10 |

Level of study | M/7 |

Teaching block(s) |
Teaching Block 2 (weeks 13 - 24) |

Unit director | Dr. Armour |

Open unit status | Not open |

Pre-requisites | |

Co-requisites |
None |

School/department | Department of Electrical & Electronic Engineering |

Faculty | Faculty of Engineering |

This unit addresses modern wireless communication systems. The first part focuses on adaptive equalisation algorithms to receive data streams in a time-dispersive multipath channel. The material addresses filter based (LTE and DFE) and non-filter based (MLSE and Viterbi) solutions. For the filter based techniques, equaliser weight training based on zero-forcing, MMSE, LMS and RLS algorithms are covered. Convergence issues for the LMS algorithm are addressed. The use of OFDM is developed for high data rate communications in a dispersive channel. Key concepts include sub-carrier orthogonality, frequency domain equalisation and use of a guard-time. Equations to define the optimum number of subcarriers are derived. The second part addresses rationale behind the adoption of CDMA technologies for 3G wireless systems alongside a detailed examination of the physics layer design to secure robust service delivery. In addition, hybrid capacity enhancement via Smart Antennas is considered, culminating in an exploration of multiple-input multiple-output (MIMO) architectures which are now a key enabler of many wireless standards.

**Part 1**

- Adaptive Equalisation:

Equalisation and inter-symbol interference; linear transversal equaliser (LTE); zero forced equalisation; MMSE Weiner-Hopf Equations; Automatic equaliser coefficient calculation (steepest descent, LMS and RLS algorithms); Multi-dimensional error surfaces, Eigenvalue spread and convergence; Auto and Cross correlation matrices; Decision Feedback Equaliser (DFE); MLSE and Viterbi equalisation; Markov Processes.

- OFDM:

Multi-carrier Transmission techniques; OFDM transmit and receiver block diagrams; use of FFT/IFFT blocks; Guard-Interval; Group Delay; Cyclical vs Linear convolution; ARQ and FEC; impact on power amplifier design.

**Part 2**

- Spread Spectrum:

Definition of terms and basic modes; spreading code generation and properties; spreading codes for Multiple Access; frequency hopping basics; direct sequence basics; propagation aspects of DS; rake reception; power control and systems design aspects.Overview of Qualcomms IS-95 and 3G CDMA systems.

- Smart Antennas:

Basic concepts of array processing; modes of operation (SFIR and SDMA); operational benefits; beam-forming architectures; impact of errors; spatial domain methods and direction of arrival; temporal domain methods; aspects of system design (FDD v TDD); TSUNAMI field trials; dual array architectures (MIMO); Capacity Equation, Sensitivity Analysis.

Having completed this unit, students will be able to:

- Describe the spatial-temporal radio channel and the methods required to achieve reliable high-speed digital communications
- Calculate LTE and DFE equaliser coefficients based on zero-forcing, MMSE and LMS algorithms
- Explain equaliser filter weight training algorithms and convergence properties
- Describe the MLSE and Viterbi Equaliser algorithms, including calculation of the number of states and derivation of the state transition and trellis diagrams.
- Draw OFDM transmit and receive architectures
- Explain how the guard time protects sub-carrier orthogonality.
- Calculate the optimum number of sub-carriers for an OFDM system based on expected channel conditions.
- Describe Multipath Exploitation in DS-CDMA and its implementation by means of a Rake receiver and the design trade-offs.
- Explain the sensitivity of DS-CDMA to power control errors and how this can be reduced
- Explain diversity gain through handover in DS-CDMA networks.
- List the benefits of spatial signal processing in wireless networks.
- Outline spatial channel models and common parameters.
- Interpret demonstration systems constructed to support the roll-out of this technology.
- Explain capacity and throughput enhancement through the use of MIMO.
- Discuss the sensitivity of MIMO systems to the propagation channel.

Lectures

Exam, 2 hours (100%) (All ILOs)

- Proakis, J., Digital Communications, 4th Edition, McGraw-Hill, 2000, ISBN:0071181830.

- Sklar, B., Digital Communications: Fundamentals and Applications, 2nd Edition, Prentice Hall, 2001, ISBN:0130847887.

- Haykin. S., Communication Systems, 4th Edition, John Wiley, 2000, ISBN:0471178691.

- Holma, H. and A Toskala (editors), WCDMA for UMTS: Radio Access for Third Generation Mobile Communications, J. Wiley, 2002, ISBN:0-470-84467-1

- Litva, J. and T. Kwok-Yeung Lo, Digital Beam-forming in Wireless Communications, Artech House, 1996, ISBN:0890067120

- Molisch, A.F, Wireless Communications, 2005, John Wiley and Sons Ltd, ISBN:9780470848883