A Software Radio Challenge Accelerating Education and Innovation in Wireless Communications

This Innovative Practice Full Paper presents our methodology and tools for introducing competition in the electrical engineering curriculum to accelerate education and innovation in wireless communications. Software radio or software-defined radio (SDR) enables wireless technology, systems and standards education where the student acts as the radio developer or engineer. This is still a huge endeavor because of the complexity of current wireless systems and the diverse student backgrounds. We suggest creating a competition among student teams to potentiate creativity while leveraging the SDR development methodology and open-source tools to facilitate cooperation. The proposed student challenge follows the European UEFA Champions League format, which includes a qualification phase followed by the elimination round or playoffs. The students are tasked to build an SDR transmitter and receiver following the guidelines of the long-term evolution standard. The metric is system performance. After completing this course, the students will be able to (1) analyze alternative radio design options and argue about their benefits and drawbacks and (2) contribute to the evolution of wireless standards. We discuss our experiences and lessons learned with particular focus on the suitability of the proposed teaching and evaluation methodology and conclude that competition in the electrical engineering classroom can spur innovation.Comment: Frontiers in Education 2018 (FIE 2018

Creating Tailored and Adaptive Network Services with the Open Orchestration C-RAN Framework

Next generation wireless communications networks will leverage software-defined radio and networking technologies, combined with cloud and fog computing. A pool of resources can then be dynamically allocated to create personalized network services (NSs). The enabling technologies are abstraction, virtualization and consolidation of resources, automatization of processes, and programmatic provisioning and orchestration. ETSI's network functions virtualization (NFV) management and orchestration (MANO) framework provides the architecture and specifications of the management layers. We introduce OOCRAN, an open-source software framework and testbed that extends existing NFV management solutions by incorporating the radio communications layers. This paper presents OOCRAN and illustrates how it monitors and manages the pool of resources for creating tailored NSs. OOCRAN can automate NS reconfiguration, but also facilitates user control. We demonstrate the dynamic deployment of cellular NSs and discuss the challenges of dynamically creating and managing tailored NSs on shared infrastructure.Comment: IEEE 5G World Forum 201

Envelope tracking amplification with reduced slew-rate and bandwidth envelopes

This paper presents an Envelope Tracking Power Amplifier whose architecture includes a Hybrid Envelope Amplifier (HEA) and an algorithm to adapt the envelope´s characteristics to the HEA´s limitations. The HEA attempts to combine the high efficiency of a switched amplifier with the wide band capabilities of a linear amplifier. A modified Slew Rate (SR) reduction algorithm cope with the bandwidth and SR limitations of the HEA. On the other hand, the non-linearities introduced by this Envelope Amplifier (EA) and by the dynamic supply are compensated using Digital Pre-Distortion. Results show that these non-linearities are compensable and that the architecture offers higher efficiency figures compared to the conventional linear EA

Track detection in railway sidings based on MEMS gyroscope sensors

The paper presents a two-step technique for real-time track detection in single-track railway sidings using low-cost MEMS gyroscopes. The objective is to reliably know the path the train has taken in a switch, diverted or main road, immediately after the train head leaves the switch. The signal delivered by the gyroscope is first processed by an adaptive low-pass filter that rejects noise and converts the temporal turn rate data in degree/second units into spatial turn rate data in degree/meter. The conversion is based on the travelled distance taken from odometer data. The filter is implemented to achieve a speed-dependent cut-off frequency to maximize the signal-to-noise ratio. Although direct comparison of the filtered turn rate signal with a predetermined threshold is possible, the paper shows that better detection performance can be achieved by processing the turn rate signal with a filter matched to the rail switch curvature parameters. Implementation aspects of the track detector have been optimized for real-time operation. The detector has been tested with both simulated data and real data acquired in railway campaigns.Peer ReviewedPostprint (published version

Track detection in railway sidings based on MEMS gyroscope sensors

The paper presents a two-step technique for real-time track detection in single-track railway sidings using low-cost MEMS gyroscopes. The objective is to reliably know the path the train has taken in a switch, diverted or main road, immediately after the train head leaves the switch. The signal delivered by the gyroscope is first processed by an adaptive low-pass filter that rejects noise and converts the temporal turn rate data in degree/second units into spatial turn rate data in degree/meter. The conversion is based on the travelled distance taken from odometer data. The filter is implemented to achieve a speed-dependent cut-off frequency to maximize the signal-to-noise ratio. Although direct comparison of the filtered turn rate signal with a predetermined threshold is possible, the paper shows that better detection performance can be achieved by processing the turn rate signal with a filter matched to the rail switch curvature parameters. Implementation aspects of the track detector have been optimized for real-time operation. The detector has been tested with both simulated data and real data acquired in railway campaigns.Peer Reviewe