29th ARRL and TAPR Digital Communications Conference

September 24-26, 2010, Vancouver, Washington

D-STAR Introduction
By John Hays, K7VE

Abstract: The D-STAR protocol provides a means to transmit Digital Voice using the AMBE codec and also 128 Kbps digital data.

Presentation Slides 

D-STAR for the Technically Curious
By John Hays, K7VE

Abstract: A quick overview of current development projects and building blocks for the D-STAR experimenter or integrator. From dongles, digital-voice adapters, node adapters, and mini-hotspots to open-source GMSK encoder/decoder and open-source Realtime Routing Updates.

Presentation Slides

D-RATS: Speaking Winlink and AX.25
By Dan Smith, KK7DS

Abstract: (Quick) overview of D-RATS messaging, Winlink 2000 Worldwide radio email system, and AX.25 TNC requirements.

Presentation Slides 

Mobile Fading;
By Sachin Dubey and Kanchan Cecil

Abstract: In wireless communication systems, the direct signal and the reflected signals form an interference pattern resulting in a received signal given by the sum of these components. They are distinguished by their Doppler shifts at the mobile. Once the slowly varying parameters associated with these components are determined, the fading coefficients can be accurately predicted far ahead. This novel approach to fading channel prediction is combined with transmitter signal optimization to mitigate the effects of “deep fades”, which severely limit the performance of mobile radio systems. This capability will potentially help to reduce power requirements for wireless channels and improve the system performance.

Proceedings Paper

RF to Video Converter for Timex/Sinclair Computers
By John M. Franke, WA4WDL

Abstract: I recently rediscovered my cache of Timex/Sinclair TS-1000 computers. I had always figured they would be handy for controller purposes. Yes, PIC chips are powerful and low cost, but the Timex/Sinclair devices were in hand, I did not need a separate computer and software package to program them, and using retro computer technology from the early 1980s would be cool. Like many early microprocessor based computers, the Timex/Sinclair devices were designed to use a regular color or B&W television set for the monitor. However, modern television receivers do not have AFC or the mechanical fine tuning capability required to handle free-running (non-crystal controlled) video modulators. I could have dissected the TS-1000 and intercepted the video just ahead of the modulator, as has been done by others, but I wanted to modify the computers as little as possible. The modulation format is either European or American and the RF output is on lower VHF channels (2 or 3) or a mid UHF channel (33).

Proceedings Paper

Robotic Radio and CW Robot, a Building Block for Robotic Radio
By Rob Frohne, KL7NA, Walla Walla University

Abstract: Look Ma! No hands! My radio is logging stations by itself. Robotic Radio is an exciting new fronteir in amateur radio. This paperintroduces the idea of Robotic Radio and overviews some of the open source software and hardware blocks useful in this area.

Proceedings Paper

SDR Cube: A Portable Software Defined Radio Utilizing An Embedded DSP Engine for Quadrature Sampling Transceivers;
By George L. Heron, N2APB and Juha Niinikoski, OH2NLT

Abstract: Software Defined Radio (SDR) in the Amateur Radio community has been making great strides in recent years. From the innovative and ground-breaking products of Gerald Youngblood, KSDR of Flex Radio some four years ago, to the most recent state-of-the-art designs in the HPSDR group, SDR technology has really now come of age. This current state-of-the-art has also been greatly enabled by the tireless work of Tony Parks, KB9YIG, the father of the Softrock designs, has enabled many thousands of hams worldwide with his series of inexpensive radios that work with a PC sound cards.

However throughout all the excitement of PC-based software defined radio, there has also been a quieter background quest for a form of SDR that is not tethered to a PC. This paper chronicles and describes the path that our team has been taking, resulting in what we call the “SDR Cube.”

Proceedings Paper 

A Simple SDR Receiver
By Michael Hightower, KF6SJ

Abstract: This article discusses the design and operation of an HF radio receiver operating in the 3.5 to 18 MHz range. The receiver architecture is based on software defined radio techniques and incorporates a Cypress PSoC CY8C3866 component that contains both analog and digital circuits, thus decreasing the receiver’s component count.

Proceedings Paper 

Testing a Digital-ATV Station using DVB-S
By Ken Konechy, W6HHC and Robbie Robinson, KB6CJZ, Orange County Amateur Radio Club (OCARC) and COAR RACES

Abstract: Most ham radio Amateur Television (ATV) stations and repeaters in use today still utilize analog technology. At the 2009 Digital Communications Conference, the authors presented a paper on “Planning a Digital-ATV Station for DVB-S”. Now, the authors present the results that were obtained by testing and using the DATV station they had planned. The purpose of this paper is to explain how to set-up and test a Digital-ATV (DATV) station to other hams…and to demonstrate the performance that can be achieved by using DATV. The authors learned a lot about different aspects of DATV during this project. We needed to dig into video resolution standards, better understand the inner workings of MPEG-2 latency, and develop a clearer understanding of the effect of peak-to-average power as related to de-rating a power amplifier for QPSK modulation.

The testing by the authors demonstrates that DATV really does produce higher-quality video than analog-ATV under adverse path conditions!!

Proceedings Paper   –   PowerPoint Slides 

Demand and Transmission of E-mail Reception Report in Digital Modes
By Patrick Lindecker, F6CTE

Abstract: The author of this paper (Patrick Lindecker F6CTE) has introduced, in the Multipsk 4.18 version (issued on the 17 of June 2010), the ability to request a reception report and to supply it by e-mail. This can be sent either by the other Ham with who you are in QSO or by a SWL monitoring your QSO.

Proceedings Paper

Technical Aspects of RS ID and Call ID and Use
By Patrick Lindecker, F6CTE

Abstract: This paper will explain why to use RS ID, the RS ID origin, description, main use and maintenance. A description of Call ID is presented, as well as an explaination of its main use.

Proceedings Paper 

Five Port Router for Network on Chip
By Swati Malviya and Anurag Jaiswal

Abstract: Multiprocessor system on chip is emerging as a new trend for System on chip design but the wire and power design constraints are forcing adoption of new design methodologies. Researchers pursued a scalable solution to this problem i.e. Network on Chip (NOC). Network on chip architecture better supports the integration of SOC consists of on chip packet switched network. Thus the idea is borrowed from large scale multiprocessors and wide area network domain and envisions on chip routers based network. Cores access the network by means of proper interfaces and have their packets forwarded to destination through multihop routing path. In order to implement a competitive NOC architecture, the router should be efficiently design as it is the central component of NOC architecture. In this paper we implement a parallel router which can support five requests simultaneously. Thus the speed of communication can be increased after reducing communication bottleneck by using simplest routing mechanism, flow mechanism and decoding logic.

Proceedings Paper 

Simulation & Synthesis of Five Port Router
By Swati Malviya and Anurag Jaiswal

Abstract: In the previous paper “Five Port Router for Network on Chip,” we design the router for Network on Chip (NoC) design, which was supporting five parallel connections at the same time simultaneously. Since each input channel and output channel of each five port is having its control and decoding logic, so five requests can be granted at the same time by reducing communication bottleneck and thus increases the performance of router. In this paper, we are coding the router in VHDL (VHSIC Hardware Descriptive language) and doing its simulation in modelsim5.1 and its Synthesis in Xilinx 6.1 version.

Proceedings Paper 

RMS Express – A Multimode Winlink 2000 User Client Program
By Victor Poor, W5SMM/AAA9WL

Abstract: RMS Express is a new multimode user client for accessing the Winlink 2000 (WL2K) network. Originally developed to aid in the development of the WINMOR radio protocol, it has grown to become a fully featured Winlink 2000 user client, offering support for telnet, packet, Pactor II and III, and WINMOR access to the WL2K system.

Proceedings Paper 

Introducing APRSSpeak: An APRStt implementation
By Douglas D. Quagliana, KA2UPW/5

Abstract: AbstractAPRSSpeak is a software implementation of Bob Bruninga’s APRStt specification for translatingDTMF digits into APRS AX.25 packets. The computer program runs on a generic PC with the soundcard connected to a two meter transceiver and the serial port connected to a TNC, which is connected toa second two meter transceiver.

Proceedings Paper 

A Comparison of Different TCP/IP and DTN Protocols Over the D-Star Digital Data Mode
By John Ronan, EI7IG and Cathal O’Connor, Waterford Institute of Technology

Abstract: This paper examines the performance of the Digital Smart Technologies for Amateur Radio-Digital Data mode with various IP and non-IP based protocols. A throughput comparison was performed between IPv4, IPv6, the DTN Convergence Layer and the NORM Convergence Layer. The experimental results show that the DTN NORM Convergence Layer exhibits better performance than TCP/IP, and appears to perform better over difficult radio links.

Proceedings Paper

Bidirectional Low Frequency Transverter (Bi-LIF) Computer Interface for Demodulation and Modulation of Radio Signals
By Alex Schwarz, VE7DXW

Abstract: The concept of a Bi-LIF (Bidirectional Low Intermediate Frequency) transverter and MDSR (Modulation /Demodulation Software Radio) was developed to provide a cost effective and easy to use interface between a computer’s soundcard and a transceiver. Most amateur radio operators already own a computer and a radio and the Bi-LIF connects the two together at the IF level. This allows a software application that uses a DSP (Digital Signal Processing) synthesizer engine, which was developed in Visual Basic and Java to modulate/demodulate the out/incoming IF. All the results and parameters of the transceiver can be displayed on the computer monitor. In receive mode, the demodulated audio can be heard in the computer’s headset. In transmit mode the headset’s microphone is used as the input device. Since all this is done in software, it is conceivable that all types of digital modulations and demodulations can be performed in the computer and then sent to/received by the transceiver.

My goal was to make a small high-speed digital signal processor that can be embedded in amateur radio devices.

Proceedings Paper

Terrestrial Link Budgets for Digital Communications
By Robert Swenson,KF4DII

Abstract: The purpose of this paper is to provide a basic understanding of how to prepare a link budget for the purpose of verifying proper data transfer, at least at acceptable error rates, of a digital RF communication system. Although some of the issues discussed may be outside those normally encountered at amateur radio bands, their discussion may provide some useful background information for the reader. Basis equations are provided.

Proceedings Paper 

The Effects of Authentication on AX.25 Packet Radio Data Transmission Time
By Paul D. Wiedemeier, Ph.D., KE5LKY , University of Louisiana at Monroe, Computer Science and Computer Information Systems Department

Abstract: This paper quantifies the time required to transmit 4 Kilobyte (KB), 8 KB, and 16 KB text files over a 2-meter AX.25 packet radio network using Gnu Privacy Guard (GPG), Secure Socket Layer and Transport Layer Security (SSL/TLS), and Internet Protocol Security (IPsec) authentication software. Our results show that less time is required to transmit data using GPG authentication than either SSL/TLS authentication or IPsec authentication. The discussion contained in this paper will benefit those amateur radio operators who provide data communication for organizations that have signed a Memorandum of Understanding with the American Radio Relay League, such as the American Red Cross and the Salvation Army.

Proceedings Paper   –   Presentation Slides 

Introduction to Digital Voice over HF
By Mel Whitten, K0PFX

Abstract: Introduction to HF Digital Voice shows the evolution of the mode developed by Cesco, HB9TLK and his work that provided users with free sound card based Hamdream, WinDRM and FDMDV programs. In addition, analog to digital basics are given, modulation techniques and an introduction to Digital Radio Mondiale (DRM) and how Hamdream and WinDRM evolved from DRMs Dream open source program. Hardware based DV is introduced with the AOR based ARD9000/9800 Fast Radio Modems.

Presentation Slides

Codec2: An Open Future for Digital Voice
By Bruce Perens, K6BP and David Rowe, VK5DGR

Abstract: When JARL designed D-STAR and ICOM productized it, they used what was available. There wasn’t a good Open codec, so they used AMBE+. It’s not their fault. They used what they could get, and there wasn’t much understanding of “open” at the time, and Open Source wasn’t so clear a success as it is now. But the “non-open” codec decision left us with some problems. Hams are constrained by AMBE+’s intellectual property protection to buy and use AMBE+ chips if we are to interoperate with D-STAR voice.

The dominant working paradigm today for digital operation in Amateur Radio is to build a software-only implementation from input to modulation, all in Open Source. I proposed a Codec2 project to solve the problem by creating a technically acceptable voice codec in an Open Source implementation, and to eventually bring its bit-stream and algorithm to an open standard.

Presentation Slides 

How the Other Half Lives: Developing SDR Software for the Macintosh Platform
By Jeremy McDermond, J.D., NH6Z

Abstract: Review of the differences and the tools available in a MAC enviroment to program for SDR. Includes Goals of MacHPSDR and OpenHPSDR software.

Presentation Slides

DSP – A Short Course
By Rick Muething, KN6KB

Abstract: Session 1 of this short course covers a DSP Intro and Basics. Session 2 covers DSP Tools and Filters. Session 3 covers how to use DSP. Session 4 covers Tricks of the DSP trade.

Seminar-session 1    Seminar-session 2    Seminar-session 3    Seminar-session 4