Professor Tim O'Farrell
PhD, MSc, BSc
Department of Electronic and Electrical Engineering
Chair in Wireless Communication
Communications Research Group


+44 114 222 5193
Full contact details
Department of Electronic and Electrical Engineering
- Profile
-
I received my BSc degree in Electrical and Electronic Engineering from the University of Birmingham and my MSc and PhD degrees in Electrical and Electronic Engineering from the University of Manchester, respectively.
Currently, I am Chair Professor of Wireless Communications at the University of Sheffield.
My research is focused on wireless communications systems specialising in physical layer signal processing, radio resource management and wireless network planning.
I have pioneered research on energy efficient mobile cellular communications, the mathematical modelling of CSMA based MAC protocols for WiFi, iterative block coding for wireless communication systems and spreading sequence design for CDMA wireless communications.
I was an entrepreneur, being the cofounder and CTO of Supergold Communication Limited (1997-2007), a start-up that participated in the standardisation of IEEE 802.11g with the M-ary Bi-Code Keying proposal.
In the framework of Mobile VCE, I was the Academic Coordinator of the Core 5 Green Radio project (2009-2012) and a leader in establishing energy efficiency as a global research field in wireless communications systems.
I have led 21 major research projects as the principal investigator and participated in 2 as a coinvestigator with a total research spend of approximately £12M.
My current EPSRC project portfolio includes the FARAD and SERAN projects as well as CommNet2.
I have published 312 journal & conference papers, book chapters, patents and technical reports; graduated 23 Ph.D. and M.Phil. students; and participated in standards, consultancy and expert witness activities within the wireless sector.
Currently, I am leading the UK Research Strategy Community Organisation in Communications, Mobile Computing and Networking within the EPSRC portfolio.
I am also a Director of the mVCE, a Chartered Engineer and a member of the IET and IEEE.
- Qualifications
-
- PhD Electrical and Electronic Engineering, University of Manchester
- MSc Electrical and Electronic Engineering, University of Manchester
- BSc Electrical and Electronic Engineering, University of Birmingham
- Research interests
-
- Multiple-access (OFDMA, CDMA & MC-CDMA)
- Forward error correction coding and iterative decoding
- Adaptive coding and modulation
- MIMO and Massive MIMO techniques
- Spreading sequence design
- Wireless visible light communication
- Energy and spectrum efficient wireless networking
- MAC and packet scheduling techniques
- Radio access network planning and optimisation (2G, 3G, 4G & 5G)
- Large scale dynamic system level simulation (WCDMA, HSPA, LTE, LTE-Advance, 5G)
- Video quality of service
- Publications
-
Journal articles
- Vector Coding Optical Wireless Links. Journal of Lightwave Technology, 1-11.
- Optimized Multi-Primary Modulation for Visible Light Communication. Journal of Lightwave Technology, 40(22), 7254-7264.
- Editorial : A decade of Green Radio and the path to “Net Zero” : a United Kingdom perspective. IEEE Transactions on Green Communications and Networking, 6(2), 657-664.
- Irregular vector turbo codes with low complexity. EURASIP Journal on Wireless Communications and Networking, 2022.
- Concurrent Multiband Direct RF Sampling Receivers. IEEE Transactions on Wireless Communications, 1-1.
- Optical energy-constrained slot-amplitude modulation for dimmable VLC: suboptimal detection and performance evaluation. IEEE Transactions on Wireless Communications, 20(3), 1582-1595. View this article in WRRO
- Non-Iterative Downlink Training Sequence Design Based on Sum Rate Maximization in FDD Massive MIMO Systems. IEEE Access, 8, 108731-108747.
- Low-profile independently- and concurrently-tunable quad-band antenna for single chain sub-6GHz 5G new radio applications. IEEE Access, 7, 183770-183782. View this article in WRRO
- Direct antenna modulation for high-order phase shift keying. IEEE Transactions on Antennas and Propagation. View this article in WRRO
- On the Local Delay and Energy Efficiency of Clustered HetNets. IEEE Transactions on Vehicular Technology, 68(3), 2987-2999. View this article in WRRO
- Systems Analysis of a Pattern Reconfigurable Antenna for Capacity Improvement of Cell Edge Users in Cellular Networks. IEEE Transactions on Vehicular Technology, 67(12), 11848-11857. View this article in WRRO
- Energy-Constrained Slot-Amplitude Modulation With Dimming Support. IEEE Photonics Technology Letters, 30(14), 1301-1304. View this article in WRRO
- Coded color shift keying with frequency domain equalization for low complexity energy efficient indoor visible light communications. Physical Communication, 31, 160-168.
- An Independently Tunable Tri-Band Antenna Design for Concurrent Multiband Single Chain Radio Receivers. IEEE Transactions on Antennas and Propagation, 65(12), 6290-6297. View this article in WRRO
- Performance Evaluation of Turbo Codes in High Speed Downlink Packet Access Using EXIT Charts. International Journal of Future Generation Communication and Networking, 10(8), 1-14.
- Bit-Error-Rate Performance of Quadrature Modulation Transmission Using Reconfigurable Frequency Selective Surfaces. IEEE Antennas and Wireless Propagation Letters, 16, 2038-2041. View this article in WRRO
- A proxy acknowledgement mechanism for TCP variants in mobile ad hoc networks. Journal of Communications and Networks, 18(2), 238-245.
- HetNets With Random DTX Scheme: Local Delay and Energy Efficiency. IEEE Transactions on Vehicular Technology, 65(8), 6601-6613. View this article in WRRO
- Reverse glacier motion during iceberg calving and the cause of glacial earthquakes. Science, 349(6245), 305-308. View this article in WRRO
- Dynamics of glacier calving at the ungrounded margin of Helheim Glacier, southeast Greenland. Journal of Geophysical Research F: Earth Surface. View this article in WRRO
- A High-Resolution Sensor Network for Monitoring Glacier Dynamics. IEEE Sensors Journal, 14(11), 3926-3931. View this article in WRRO
- An enhanced color shift keying modulation scheme for high-speed wireless visible light communications. Journal of Lightwave Technology, 32(14), 2582-2592. View this article in WRRO
- Relay deployment in cellular networks: planning and optimisation. IEEE Journal on Selected Areas of Communications, 30(11), 1-10.
- Dynamic Cell Expansion with Self-Organizing Cooperation. IEEE Journal on Selected Areas of Communication, 31(5), 851-860.
- Pilot-aided estimation and equalisation of a radio-over-fibre system in wideband code division multiple access. IET Communications, 7(10), 999-1007. View this article in WRRO
- Energy efficient coordinated radio resource management: A two player sequential game modelling for the long-term evolution downlink. IET Communications, 6(14), 2239-2249.
- Small-Net vs. Relays in a heterogeneous low energy LTE architecture. Journal of Communications, 7(SPL.ISS. 10), 716-725.
- Guest Editorial. Journal of Communications, 7(SPL.ISS. 10), 713-715.
- Low energy indoor network: deployment optimisation. EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING.
- Dynamic basestation antenna design for low energy networks. Progress In Electromagnetics Research C, 31, 153-168.
- Achieving service differentiation in IEEE 802.11e enhanced distributed channel access systems. IET Communications, 6(7), 740-750.
- Performance analysis of DSRC priority mechanism for road safety applications in vehicular networks. Wireless Communications and Mobile Computing, 11(7), 980-990.
- Throughput and Delay Analysis for p-Persistent CSMA with Heterogeneous Traffic. IEEE T COMMUN, 58(10), 2881-2891.
- Design and evaluation of a high data rate optical wireless system for the diffuse indoor channel using barker spreading codes and RAKE reception. IET COMMUN, 2(1), 35-44.
- Distributed MAC protocol for delay QoS provisioning in 3GRANs. ELECTRON LETT, 41(5), 257-259.
- Low-complexity medium access control protocols for QoS support in third-generation radio access networks. IEEE T WIREL COMMUN, 4(2), 743-756.
- Complementary sequence inverse keying for indoor wireless infrared channels. ELECTRON LETT, 40(4), 257-259.
- Application of complementary sequences in indoor wireless infrared communications. IEE P-OPTOELECTRON, 150(5), 453-464.
- Families of ternary sequences with aperiodic zero correlation zones for MC-DS-CDMA. ELECTRON LETT, 38(25), 1660-1661.
- Concordat: Towards better researchers. Engineering Science and Education Journal, 6(4), 167-170.
- Adaptive error control for broadcast DS/SSMA packet radio networks. Electronics Letters, 32(3), 161-161.
- Switched correlator receiver architecture for optical CDMA networks with bipolar capacity. Electronics Letters, 31(11), 905-906.
- Channel sense spread spectrum with overload detection against FFDS: A delay/throughput comparison. Electronics Letters, 30(22), 1872-1874.
- Performance analysis of an optical correlator receiver for SIK DS-CDMA communication systems. Electronics Letters, 30(1), 63-65.
- Analysis of DS/SSMA for indoor radio communication in a log-normal fading channel. Electronics Letters, 29(13), 1204-1204.
- Throughput analysis of a CDMA protocol with channel sensing and overload detection for fibre optic LANs. Electronics Letters, 29(20), 1782-1782.
- Visualizing environmental data at the EPA. IEEE Computer Graphics and Applications, 13(2), 34-38.
- New Signature Code Sequence Design Techniques For Cdma Systems. Electronics Letters, 27(4), 371-373.
- Delay/Throughput Performance Analysis Of The Code-Division Multiple-Access (CDMA) Protocol In Optical Fibre Lans. Fibre Optics '89.
- A system‐level performance evaluation of a reconfigurable filtenna in the presence of in‐ and out‐of‐band blockers. IET Communications.
- Near Capacity Irregular Turbo Code. Indian Journal of Science and Technology, 8(23). View this article in WRRO
Chapters
- Toward Green Evolution of Cellular Networks by High Order Sectorisation and Small Cell Densification, Advances in Wireless Technologies and Telecommunication (pp. 1-28). IGI Global
- Green Communication Concepts, Energy Metrics and Throughput Efficiency for Wireless Systems, Green Communications (pp. 19-42). John Wiley & Sons, Ltd
Conference proceedings papers
- The Volume Spectral and Energy Efficiency of Ultra-Dense IoT Networks with Clustered Users. 2022 20th International Symposium on Modeling and Optimization in Mobile, Ad hoc, and Wireless Networks (WiOpt), 19 September 2022 - 23 September 2022.
- Machine Learning-Assisted Optimization of a Metasurface-Based Directly Modulating Antenna. 2022 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S/URSI), 10 July 2022 - 15 July 2022.
- The Spectral and Energy Efficiency of Ultra-Dense IoT Networks. 2022 IEEE 8th International Conference on Network Softwarization (NetSoft), 27 June 2022 - 1 July 2022.
- The effect of ADC resolution on concurrent, multiband, direct RF sampling receivers. 2021 IEEE Global Communications Conference (GLOBECOM), 7 December 2021 - 11 December 2021.
- Metasurface Direct Antenna Modulators in non-Line of Sight Channels for the Internet of Things. 2020 IEEE 31st Annual International Symposium on Personal, Indoor and Mobile Radio Communications, 31 August 2020 - 3 September 2020.
- Direct Antenna Modulator for m-QAM Applications. 2020 14th European Conference on Antennas and Propagation (EuCAP), 15 March 2020 - 20 March 2020.
- Tri-band Single Chain Radio Receiver for Concurrent Radio. 2020 2nd 6G Wireless Summit (6G SUMMIT), 17 March 2020 - 20 March 2020.
- Planar Frequency-Tunable Quad-Band Antenna with Independently Controllable Bands. 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, 7 July 2019 - 12 July 2019. View this article in WRRO
- Tuning Range Enhancement of a Frequency-Agile Tri-band Slot Antenna. 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, 7 July 2019 - 12 July 2019. View this article in WRRO
- Performance Evaluation of Generalized Optical Spatial Modulation with Dimming Support. 2018 IEEE Globecom Workshops (GC Wkshps), 9 December 2018 - 13 December 2018.
- An Energy Efficiency Evaluation Framework for Radio Access Networks. 2018 International Conference on Information and Communication Technology Convergence (ICTC), 17 October 2018 - 19 October 2018.
- White Light Constrained Multi-Primary Modulation for Visible Light Communication. 2017 IEEE GLOBECOM WORKSHOPS (GC WKSHPS) View this article in WRRO
- Multiband Tunable MIMO Antenna. Loughborough Antennas & Propagation Conference 2018 (LAPC 2018)
- A low-complexity array of directly phase modulating antennas. 12th European Conference on Antennas and Propagation (EuCAP 2018)
- 5G Reconfigurable Antennas. 12th European Conference on Antennas and Propagation (EuCAP 2018)
- A low-loss reconfigurable Frequency Selective Surface based antenna for Direct Antenna Modulation. Loughborough Antennas & Propagation Conference (LAPC 2017) View this article in WRRO
- Concurrent, Multi-Band, Single-Chain Radio Receiver for High Data-Rate HetNets. 2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), 24 September 2017 - 27 September 2017. View this article in WRRO
- Tunable, concurrent multiband, single chain radio architecture for low energy 5G-RANs. 2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 15 May 2017 - 19 May 2017. View this article in WRRO
- Concurrent, Tunable, Multi-Band, Single Chain Radio Receivers for 5G RANs. 2017 IEEE 85th Vehicular Technology Conference (VTC Spring), 4 June 2017 - 7 June 2017. View this article in WRRO
- Frequency selective surface loaded antenna for direct antenna modulation. 2017 11th European Conference on Antennas and Propagation (EUCAP), 19 March 2017 - 24 March 2017. View this article in WRRO
- Direct Antenna Modulation with Frequency Selective Surfaces. 5th Colloquium on Antennas, Wireless and Electromagnetics (CAWE 2017)
- Tuneable dual-band antenna for sub 1 GHz cellular mobile radio applications. 2016 Loughborough Antennas & Propagation Conference (LAPC), 14 November 2016 - 15 November 2016. View this article in WRRO
- Demonstration of RF Digitising Concurrent Dual-Band Receiver for Carrier Aggregation over TV White Spaces. 2016 IEEE 84th Vehicular Technology Conference (VTC-Fall), 18 September 2016 - 21 September 2016. View this article in WRRO
- Analysis of forward error correction schemes for colour shift keying modulation. 2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 30 August 2015 - 2 September 2015.
- Non-saturated throughput analysis for a QoS differentiated p-persistent CSMA protocol with the capture effect. 2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 30 August 2015 - 2 September 2015.
- A comparative study of energy efficiency between MIMO and SISO based LTE RANs. 2015 IEEE International Conference on Communications (ICC), 8 June 2015 - 12 June 2015.
- Energy efficiency in 5G access networks: Small cell densification and high order sectorisation. 2015 IEEE International Conference on Communication Workshop (ICCW), 8 June 2015 - 12 June 2015.
- Performance Evaluation of Spatial Complementary Code Keying Modulation in MIMO Systems. 2015 IEEE 81st Vehicular Technology Conference (VTC Spring), 11 May 2015 - 14 May 2015.
- Higher Order Colour Shift Keying Modulation Formats for Visible Light Communications. 2015 IEEE 81st Vehicular Technology Conference (VTC Spring), 11 May 2015 - 14 May 2015.
- Analysis of the use of beam reconfigurable antennas in a homogeneous cellular network deployment. 2014 Loughborough Antennas and Propagation Conference (LAPC), 10 November 2014 - 11 November 2014.
- A dynamic basestation antenna with reconfigurable azimuth beamwidth. 8th European Conference on Antennas and Propagation, EuCAP 2014 (pp 1889-1892)
- A dynamic basestation antenna with reconfigurable azimuth beamwidth. The 8th European Conference on Antennas and Propagation (EuCAP 2014), 6 April 2014 - 11 April 2014.
- Efficiency metrics for wireless communications. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC (pp 2825-2829)
- Energy consumption of 4G cellular networks: A london case study. IEEE Vehicular Technology Conference
- View this article in WRRO
- A robust wide-area wireless sensor network for GNSS monitoring of flowing glaciers. 2012 Loughborough Antennas & Propagation Conference (LAPC), 12 November 2012 - 13 November 2012.
- Implementation trade-offs of fountain codes in LTE and LTE-A. 2012 7th International ICST Conference on Communications and Networking in China, CHINACOM 2012 - Proceedings (pp 419-424)
- Throughput and delay analysis of a qos differentiated p-persistent CSMA protocol with multirate. IEEE Vehicular Technology Conference
- Optimising femtocell placement in an interference limited network: Theory and simulation. IEEE Vehicular Technology Conference
- Two-tier cellular networks with frequency selective surface. Proceedings of the 14th IEEE International Conference on High Performance Computing and Communications, HPCC-2012 - 9th IEEE International Conference on Embedded Software and Systems, ICESS-2012 (pp 740-747)
- Dynamic cell expansion: Traffic aware low energy cellular network. IEEE Vehicular Technology Conference
- Integrated cross-layer energy savings in a smart and flexible cellular network. 2012 1st IEEE International Conference on Communications in China Workshops, ICCC 2012 (pp 79-84)
- Energy efficiency evaluation of SISO and MIMO between LTE-femtocells and 802.11n networks. IEEE Vehicular Technology Conference
- Long term evolution downlink packet scheduling using a novel proportional-fair-energy policy. IEEE Vehicular Technology Conference
- Capacity-energy-cost tradeoff in small cell networks. IEEE Vehicular Technology Conference
- Energy efficiency and spectral efficiency trade-off of a novel interference avoidance approach for LTE-femtocell networks. IEEE Vehicular Technology Conference
- Power-capacity-tradeoff for low energy interference limited cellular networks. IEEE Vehicular Technology Conference
- Green cellular network: Deployment solutions, sensitivity and tradeoffs. 2011 Wireless Advanced, WiAd 2011 (pp 42-47)
- Scalability of two-way relay channel network coding in a relay enhanced LTE cell. 11th International Symposium on Communications and Information Technologies, ISCIT 2011 (pp 168-173)
- SFBC MIMO energy efficiency improvements of common packet schedulers for the long term evolution downlink. IEEE Vehicular Technology Conference
- A new adaptive differentiated p-persistent CSMA protocol that reduces the effect of the transmission errors on the system throughput performance. IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference (pp 2181-2185)
- Throughput and delay analysis for a differentiated p-Persistent CSMA protocol with the capture effect. IEEE Vehicular Technology Conference
- Practical network coding for two way relay channels in LTE networks. IEEE Vehicular Technology Conference
- Energy efficient architectures and techniques for green radio access networks. 2010 5th International ICST Conference on Communications and Networking in China, ChinaCom 2010
- A characterisation of HSDPA capacity using EXIT chart techniques. NGMAST 2009 - 3rd International Conference on Next Generation Mobile Applications, Services and Technologies (pp 204-208)
- Sensorless speed measurement of induction machines using short time fourier transformation. SPEEDAM 2008 - International Symposium on Power Electronics, Electrical Drives, Automation and Motion (pp 1114-1119)
- Performance analysis of PDC-OCDMA system with APD mismatch. Communications in Computer and Information Science, Vol. 20 CCIS (pp 306-313)
- Utran radio resource management for MPEG4 video transmission using perceptual video quality methods. IEE Conference Publication(503) (pp 674-677)
- MPEG-2 video streaming over IEEE 802.11 gwlan in the presence of Bluetooth interference. IEE Conference Publication(503) (pp 579-583)
- Maximising spectral-efficiency in 3rd generation radio-access-networks using low-complexity multiple-access-control protocols. Third International Conference on 3G Mobile Communication Technologies
- Analysis and simulation of AM-AM/PM nonlinear distortion due to direct laser modulation in radio over fibre systems. International Topical Meeting on Microwave Photonics MWP-02, 8 November 2002 - 8 November 2002.
- Infrared wireless communications. 11th IEEE International Symposium on Personal Indoor and Mobile Radio Communications. PIMRC 2000. Proceedings (Cat. No.00TH8525)
- The performance of an optimum digital matched filter detector using structured code sequences for CDMA applications. [Proceedings] Singapore ICCS/ISITA `92
- Throughput Analysis of a Slotted Cdma Scheme with One Persistent Carrier Sensing and Collision (overload) Detection. IEEE Second International Symposium on Spread Spectrum Techniques and Applications
- Delay/throughput performance of CDMA embedded in a one-persistent channel sense and collision (overload) detection protocol. [Proceedings] Singapore ICCS/ISITA `92
Datasets
- Dataset for "Direct Antenna Modulation for high-order Phase Shift Keying" in IEEE Transactions on Antennas and Propagation.
- Data for LAPC2017 Conference Paper: A low-loss reconfigurable Frequency Selective Surface based antenna for Direct Antenna Modulation.
- An Independently Tunable Tri-band Antenna Design for Concurrent Multi-band Single Chain Radio Receivers.
Preprints
- Vector Coding Optical Wireless Links. Journal of Lightwave Technology, 1-11.
- Professional activities and memberships
-
- Director of CommNet
- External Examiner at KCL
- Research students
Student Degree Status Primary/Secondary Abukharis S H S PhD Graduated Primary Arbi A S PhD Graduated Primary Singh R PhD Graduated Primary Turyagyenda C PhD Graduated Primary Wang S PhD Graduated Primary