Details of UCC’s studentships:
Brief Project Descriptions:
Novel radio frequency power amplifiers
The performance and efficiency of the power amplifier (PA) plays a significant role in the overall efficiency and battery life of mobile wireless devices such as cellular phones and WiFi-enabled portable devices. As wireless communications standards have evolved, there has been a trend towards complex modulation schemes to improve the data throughput. Unfortunately, these complex modulation schemes give rise to output signals with a non-constant time envelope that place greater demands on the power amplifier, in terms of the trade-off between efficiency and linearity. One option to maintain linearity for these complex waveforms is to bias the PA in a linear mode which guarantees good linearity at the expense of poor efficiency, while another option is to operate the PA in a more non-linear mode giving higher efficiency but poorer linearity that needs to be compensated by predistortion techniques, adding to the system complexity. Another approach to preserve both linearity and efficiency is the use of envelope tracking techniques, in which either the bias current or the bias voltage of the power FETs in the PA are adjusted based on the power level (envelope) of the input signal. These techniques offer the possibility of achieving good PA efficiency over a wide range of power levels but rely on techniques to adjust the bias levels very quickly in response to the signal power level. This project will investigate the use of switched-mode power supply techniques (DC-DC converters) as a means of accomplishing fast envelope tracking for efficient PA design. With respect to existing wireless standards and emerging LTE (Long Term Evolution) devices, the main issues to be investigated are whether switched-mode techniques are fast enough for envelope tracking applications, whether the efficiency of the DC-DC converters themselves would be a potential source of inefficiency in the overall PA system and whether the spurious tones introduced by the switched-mode techniques can be mitigated so as not to compromise the overall distortion behaviour of the PA.
Control and network co-design approaches for emerging wireless sensor and actuator
Networked control systems are characterised by closed-loop control that is achieved over a real-time communications network. Such networks connect sensors and actuators with control systems, and are widely used in industry to automate a range of time-sensitive and safety-critical process control tasks. There is significant interest in using wireless as the communication medium for these control systems but current solutions suffer from a lack of scalability and fault-tolerance. We aim to overcome these limitations by employing a novel approach for wireless industrial control networks in which the design of the network and the control system are closely integrated.
Leveraging cloud computing for scalable management of sensor data:
Widespread deployment of sensors (as envisaged, for example, by the Internet of Things) will result in very large data sets from various sensor network sources. There is a challenge in managing this data in a manner is scalable and allows effective access to derive useful information. In addressing the challenge this project will investigate novel solutions that leverage cloud computing in combination with in-network techniques.
Details on how to apply can be requested from the listed supervisors above.