Programme

1000-1030 Prof. Dr. Michael Hartje, DK5HH and Markus Heller, M.A., DL8RDS: Introduction and Overview on Recent SDR Developments

1030-1100 Črt Valentinčič, S56GYC, Red Pitaya: HamLab

1100-1130 Erwin Rauh, DL1FY: Charly25 – SDR Transceiver Project – Community Development

Building an SDR transceiver is a new challenge of amateur radio. We show the development of a possible frontend with the associated input and output filters, and the required software for Windows and Linux. The project is based on the well-known RedPitaya Board and shows how to use the open source idea of the global 'SDR Community'.

1130-1200 Chris Dindas, DG8DP: Standalone SDR-TRX, Highend - Lowcost - Homebrew

Based on the Hermes SDR PCB it was possible to build a Standalone SDR-TRX with standard components. It will be shown how all components, like mini PC, Display, 5W Amp, Optical Encoders etc. have been placed and wired and what difficulties have been overcome in this project.

1200-1230 Lunch Break

1230-1300 Dr. Selmeczi Janos, HA5FT: A new lightweight data flow system

The idea of a new data flow system will be presented together with the ongoing development efforts and with the achieved results. The new system is substantially different from the gnu-radio system. The system uses the hierarchical synchronous data flow model with some extensions. It has a high level data flow description language, a custom compiler and a runtime system. The data flow model is hierarchical. New composite actors (i. e. the processing nodes in the data flow graph) could be created using the existing ones. The model execution uses precomputed static schedule (i. e. the execution order of the actors). The execution and the schedule are hierarchical. Each composite actor has its own schedule. The usual synchronous data flow model is extended by the use of global variable like data type, the explicit use of parameters controlling the actors, a switch construct for dynamic runtime selection among a group of actors having the same interface signature and the dynamic scaling of the number of output data elements the actors are producing. The high level language is a new one. The specification has three level: the composite actor description language, the intermediate assembly language and the binary virtual machine code level. The compiler compiles the composite actor description into virtual machine code or C language code. During the compilation it checks if the data flow is a periodic schedulable synchronous data flow and computes the schedule. The runtime system is lightweight. It runs on 64 or 32-bit Linux system on Intel and ARM processors, on Cortex-A9 and Cortex-M4 ARM processors in bare metal mode, as well as on picPIC32 processors. In the future support for GPUs and FPGAs will be added. The runtime system is capable of running several data flows in parallel. The runtime system supports more than one processing nodes. It is possible to distribute the actors on the processing nodes without recompilation simply by specifying on which node an actor should run. The runtime system could be embedded into other application for providing data flow functionality to that application. The lowest level of actors, the primitive ones, are written in C language and they use a very simple interface. The development effort is an ongoing one. The first version of the language specification which does not has the switch and output scaling extension is ready. The compiler for this specification is operational. The runtime system for executing the virtual machine code on Linux and bare metal ARM system is operational. This results verify the viability of the concept. The implementation of the additional data flow extensions, the actor distribution and the composite actor compilation into C language are under way and the experimentation with GPUs and FPGAs has been started. The major use of the system is to provide dynamically reconfigurable DSP functionality to SDR applications, to build distributed building and industrial automation systems and add data flow functionality to embedded systems.

1300-1330 Steve Hicks, N5AC, FlexRadio: Direct Sampling and Benefits of the Architecture

1330-1400 Frank Riedel, DJ3FR: The HackRF One as a Signal Generator

The usability and performance of the HackRF One SDR experimental platform as a signal generator up to 6 GHz is examined by means of an HPIB driven measurement system. The effective circuit of the HackRF One used in the CW TX mode is described and its components are linked to the parameters of the command line tool 'hackrf_transfer'. The frequency accuracy of the HackRF One is measured against a frequency standard, output signal levels and spurious emissions are determined using a spectrum analyzer.

1400-1430 Andras Retzler, HA7ILM: Demodulators from scratch: BPSK31 and RTTY

RTTY and BPSK31 digital modes have been popular on the amateur radio bands for a long time. While existing applications and frameworks (e. g. Fldigi, gMFSK, GNU Radio) allow us to decode these signals, the underlying algorithms can be applied to other modulations as well, which makes their investigation a fruitful learning experience. This presentation will guide through the steps of implementing BPSK31 and RTTY demodulators from scratch, and their integration into the OpenWebRX web interface.

1430-1500 Stefan Scholl, DC9ST: Introduction and Experiments on Transmitter Localization with TDOA

Time-Difference-of-Arrival (TDOA) is a well-known technique to localize transmitters using several distributed receivers. A TDOA system measures the arrival time of the received signal at the different receivers and calculates the transmitter’s position from the delays. The talk first introduces the basics of TDOA localization. It shows how to measure signal delay with correlation and how to determine the position using multilateration. It also covers further aspects and challenges, like the impact of signal bandwidth and errors in delay measurement, receiver placement and synchronization as well as the requirements on the network infrastructure. Furthermore, an experimental TDOA system consisting of three receivers is presented, that has been setup to localize signals in the city of Kaiserslautern, Germany. The three receivers are simple low-cost devices, each built from a Raspberry PI and a RTL/DVB-USB-Stick. They are connected via internet to a master PC, which performs the complete signal processing. The results demonstrate, that even with a simple system and non-ideal receiver placement, localization works remarkably well.

1500-1515 Coffee Break

1515-1545 Mario Lorenz, DL5MLO: Across the Solar System - using SDRs for real long-distance communication

Software Defined Radios (SDR) are nowadays found in many applications. In a typical ham radio context, they are often seen as little more than the replacement of traditional analog radios that are readily and cheaply available. Enter Deep Space Communication: The equipment used here is neither readily available to the average amateur, nor is it particularly cheap. Deep Space signal reception is thus ideally suited for SDR experiments. In this paper, we will show in detail the usage of various SDR frameworks like PothosWare and LiquidSDR together with more specialized libraries to build a Deep Space SDR receiver.

1545-1645 Derek Kozel, AG6PO, Ettus: Hardware Accelerated SDR: Using FPGAs for DSP

1645-1715 Rohde&Schwarz Engineering Competition

Presentation of the winner / winning team of the Rohde & Schwarz Engineering Competition

1715-1745 Evariste Courjaud, F5OEO: Rpitx : Raspberry Pi SDR transmitter for the masses

Low cost RTL-SDR democratize access to SDR reception, but is there an equivalent low cost solution for transmission : Rpitx is a software running on Raspberry Pi which use only GPIO to transmit HF. This presentation describes how to use it as a SDR sink but also describes details of how it is implemented using PLL available on the Raspberry Pi board. Warnings and limits of this simple SDR are also provided before going “on air”. Last paragraph shows what are potential evolutions of this system : low cost DAC and third party software integration.

1745-1800 Michael Hartje, DK5HH, and Markus Heller, DL8RDS: Final Discussion and Review