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Portable Waveform Development with

Spectra DTP4700

Vincent J. Kovarik Jr, Ph.D. – CTO August, 2015

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Introduction

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►Signal processing is performed digitally via software.

►The Software Communications Architecture (SCA) promotes portable, reusable waveforms.

►The SCA was the foundation for the Joint Tactical Radio System (JTRS) program.

►However, the initial projects encountered multiple problems including poor portability of waveforms.

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Waveform Portability

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►The SCA defines a core set of APIs related to the management and control of a radio system and the applications (waveforms) that were hosted on the system.

►However, a key element of the software architecture was overlooked – the definition of a standard set of interfaces for radio devices and services.

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► Standard interfaces for devices and services promote waveform portability by providing a consistent API across multiple platforms.

► It isolates the waveform and other applications from different I/O drivers and board support packages (BSP) for each radio platform.

Device and Service APIs

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DTP4700 System Overview

►The DTP4700 is comprised of two systems:

►Host system Thunder SDR system

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DTP4700: Host System

► Supplied as a bootable LiveUSB ► Ubuntu 12.04 LTS: ► Includes all the tools necessary to develop SCA applications

for the Thunder SDR system: ► Texas Instruments Linux DVSDK ► DataSoft’s Thunder SDK ► Spectra ORB C edition for x86, ARM and DSP ► Spectra ORB C++ edition for x86 and ARM ► Spectra Core Framework + basic DTP4700 SCA Platform ► Demonstration SCA waveform applications (FM audio and data

carrying examples with source code) ► Spectra CX (Optional) ► Spectra Probes Toolbox (Optional) ► Spectra Radio Services and Devices (Optional) – implementations of

standard JTNC APIs

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DTP4700: Thunder SDR System

► AM/DM37x OMAP based digital baseband processing system: ► ARM Cortex A8 GPP & TI C64x DSP

► Xilinx Spartan 6 FPGA

► Full duplex RF Transceiver with RF front end supporting a wide frequency range ► DTP4700H – 400 MHz to 4 GHz

► DTP4700L – 30 MHz to 1.6 GHz

► Test and Debug ► JTAG DSP/ETM assembly

► FPGA/CPLD connectors

► Tx and Rx test points

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Thunder SDR – Front Panel

TX Out RX In

SD/MMC Card Slot

USB-OTG

Ethernet 10/100

Audio In Audio Out

LEDs

Ethernet 100/1G

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Thunder SDR – Back Panel

GPS RF Antenna GPS 1PPS

In/Out

COM2 Port Fan

DC Power 9-18V

Power Switch

COM1 Port External Clock In

External Clock Out

AUX In/Out

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Baseband Subsystem

► Based on TI AM/DM37x OMAP processor and Xilinx Spartan 6 FPGA

► AM/DM37x OMAP Processor features: ► 1 GHz ARM© Cortex™ A8 RISC core

► 800 MHz C64x DSP core

► POWER SGX Graphics Accelerator

► 2000 Dhrystone MIPS – capable of supporting the RTOS and complex WFs

► DSP can be selectively powered down

► Ethernet, Gig-E, USB, SD, RS232 and audio interfaces

► Integrated GPS receiver with 1PPS output

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RF Front End Subsystem ► Full duplex with programmable signal

bandwidths from 40 KHz to 40 MHz ► Tx/Rx frequency range:

► DTP4700H – 400 MHz to 4 GHz ► DTP4700L – 30 MHz to 1.6 GHz

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► Dual-channel 12-bit 100Msps ADCs ► Dual-channel 16-bit 800Msps DACs ► TX: Quadrature modulator ► RX: Direct Conversion ► MCSP system for board-level control

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Spectra Probe Toolbox ► Data Probe

► Inject or capture GPP/DSP data stream

► Synchronize and trigger multiple probe points

► Capture block data

► Interface to MATLAB/Simulink

► Traffic Probe ► Capture and display network traffic

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► Resource Probe ► Memory and CPU utilization

graphs

► CPU resource detail

► Memory Peeks and Pokes

► Latency Probe ► Capture and display timestamp

information

► Synchronized time base across the GPP and DSP

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DTP4700 Software Stack

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Spectra CX Model Driven Development

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DTP4700 SCA Platform Model

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SCA Device Description

ExecutableDevice

The ExecutableDevice extends the LoadableDevice providing additional

interfaces to manage the processes and tasks, via Process ID (PID). This

enables the execution or termination of programs and tasks.

DSPDevice

The DSPDevice is a “proxy” ExecutableDevice that runs on the baseband

board’s GPP and is used to load and execute components on the DSP

processor.

WFFPGAProxy

The WFFPGAProxy provides the interface to send and receive waveform

signal processing data between the baseband board and the transceiver

board.

RfCtrlDevice

The RfCtrlDevice provides an SCA Device implementation of the RF front

end of the DTP4700. This device enables access to status information

and control points for the RF elements.

Standard Devices

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SCA Service Description

LogService The LogService implements the standard OMG Lightweight

Log Service used by the SCA.

EventService The EventService provides the means for send event

information between components in the system.

NamingService The NamingService implements the OMG CORBA

NamingService standard used by the SCA.

Standard Services

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SCA Device Description

EthernetDevice

The EthernetDevice provides a standard interface across

radio platforms for interacting with a physical Ethernet

device.

FrequencyReferenceDevice

This device provides a standard interface to the

frequency reference device providing the 1PPS for the

system.

SerialPortDevice The SerialPortDevice provides a standard interface to the

RS-232 supported by the platform.

GPSDevice

The GPSDevice provides a common set of interface calls

to receive and set GPS information related to the GPS

receiver.

AudioPortDevice

The AudioPortDevice provides a standard interface to

the speaker and microphone devices provided by the

radio system.

Extended Device APIs

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SCA Service Description

PacketService The PacketService provides a standard API to the IP or Ethernet

networking stack managed by the operating system.

TimingService

The TimingService implements the JTRS API providing a standard

set of calls to obtain and receive time-of-day, system time and

other time related information.

VocoderService

The VocoderService provides a standard interface and container

that enables different Vocoder implementations to be plugged

into the voice data stream.

Extended Service APIs

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In Conclusion…

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►Lack of standard interfaces to the radio platform devices and services significantly hindered JTRS waveform portability.

► JTRS APIs were developed to provide a standard set of interfaces across multiple radio systems.

►Together, the SCA and JTRS APIs provide a comprehensive set of standard interfaces between a waveform application and the radio.

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In Conclusion…

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►The Spectra DTP4700 provides a capable and flexible development system *and* a rich set of standardized APIs.

►The standard APIs simplify porting waveforms across multiple radio systems by reducing the level of code rework.

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For Additional Information

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►PrismTech Website:

►www.prismtech.com/spectra

►E-mail:

►info@prismtech.com