N5AC 2015 Ham-Com FlexRadio Technology Update

SDR Architectures, Remote Radio and FlexRadio Update

Ham-Com: June 13, 2015

Stephen Hicks, N5AC VP Engineering, FlexRadio Systems

SDR, Remote HF, FlexRadio Agenda

What is an SDR? History of Amateur SDR Technologies that make an SDR

Remote HF and Maestro FlexRadio Update Other presentations today

What is an SDR?

What is an SDR?

What is an SDR?

SDR is a spectrum

Some radios are clearly NOT

Other radios clearly ARE

Many permutations in-between

So what makes up an SDR?

Back to Basics …

Radio Magic

Back to Basics …

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

Multi-Conversion

64.455 MHz 455kHz

36kHz

3–15 kHz Roofing Filter

Distortion

DEMOD

Engineering Design Process

Draw a block diagram

Simulate

Draw a schematic

Simulate

Build

Measure and adjust

Engineering Design Process

Does the circuit match the simulation exactly? NO … WHY?

Components are not “ideal” There are losses not modeled Component variance Component capabilities

Result: Never as good as the simulation

Can’t we account for component differences?

In some cases, YES

Some materials work better in some cases

Compensating circuits can be added

In some cases, NO

There will always be issues

Components and ProblemsResistors Capacitors Inductors Transistors Mixers Amplifiers Crystals Filters

Lot Variance Parasitics Non-linearities Thermal variance Electrically induced variance IMD Manufacturing variance The list goes on…

Filtering: The Goal“Brick Wall” Filter

frequency

resp

onse

Block undesired

Pass desired

FilteringPractical limits to achievable results

Suggested capacitor model, Tantalum capacitor

Block Diagram Key

Yellow blocks are

Green blocks are DIGITAL

ANALOG

123 346 767 1134

001 1010 1011 110 010

455 913 21

2394 23

Filter Design: SimulationSampled signals passed through simulated ideal components

Results could even be played out a speaker

123 346 767 1134 1582 1204 895 431 208

150 300 600 1200 1500 1200 600 300 150

FILTER SIMULATION DAC

Filter Design: Simulation Limits

Analog: 20-30 poles

Digital: unlimited … except for latency. Maybe 200, 1000, more!

Could a computer run the simulation IN THE RADIO?

ADC DACFILTER SIMULATION

Presto: Software in the Radio

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

FILTER

Is this an SDR?

ADC DAC

DEFINITIONS: Software Defined vs. Controlled

CONTROLLED

Computer Control of Fixed Capabilities(frequency, band, etc)

DEFINED

Modulation, Demodulation, filtering, and processing; as well as Control Capabilities Software Defined and Upgradeable

Filter Shape Factor

FLEX-‐5000 Note Brick Wall & Flatness

Radio Y

Radio Z

Radio X

500 Hz Brick Wall Filter

6dB Bandwidth 487 Hz, 60dB Bandwidth 660 Hz, Shape Factor ~1.35 4096 Bin FFT and 2048 Tap Filter

2.8KHz SSB Filter Spectrum

6dB Bandwidth 2587 Hz, 60dB Bandwidth 2756 Shape Factor ~1.06, 2048 Tap Filter

Software Demodulation

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

FILTER

Now, is this an SDR?

ADC

DAC

Software Demodulation and Baseband

New demod schemes added later!

Precise Filtering

Advanced Noise Reduction

DEMOD

IF AMP

AUDIO AMP

FILTER DAC

ADC

PowerSDR - A FlexRadio Original!

Economics 101

What is the marginal cost of a 2nd receiverin an analog radio?

ANSWER: the cost of the added parts (plus amortized engineering)

What if I want 2 RX?

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

FILTER

2x analog components ≈ $2x

ADC

DAC

DEMODADC

FILT

ER

What are we trying to achieve?

Remove distortion

Better performance

Flexibility to change or add features

Ability to tailor the radio quickly

Never before possible noise mitigation

Never before possible capabilities

Can we do more?

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

FILTER

What about this analog stuff?

DAC

ADC

Direct Sampling

LO

DEMOD

FILTER

AUDIO AMP

MIXER

FILTER

Now, THAT’s an SDR!

DAC

ADC

LO

DEMOD

FILTER IF AMP

AUDIO AMP

MIXER

FILTER

Why doesn’t everyone do Direct Sampling?192kHz @ 64bits =

12Mbps192kHz

DAC

ADC

10Mbps

Direct Sampling

LO

DEMOD

FILTER

AUDIO AMP

MIXER

FILTER


250MHz @ 16bits = 4Gbps

250MHz

DAC

ADC

4Gbps is…

40 - 100Mbps cables4 - 1Gbps cables

That’s a LOT of data! The most modern home networking you can buy, can’t handle this …

Economics 101

What is the marginal cost of a 2nd receiverin an digital radio (SDR)?

ANSWER: the cost of the extra processing power (plus amortized engineering) … think Moore’s law

Processing Power = FPGA

Direct Sampling

LO

DEMOD

FILTER

AUDIO AMP

MIXER

FILTER


ALL of HF digitizedALL of HF

DAC

ADC

Direct Sampling

NCO

DEMOD

FILTER

AUDIO AMP

MIXER

How many do you want?

DAC

ADC

DEMOD

FILTER

MIXER

Direct Sampling Benefits

+ Distortion minimized (ADC @ antenna): best signal clarity + n-Receivers, n-Panadapters and varying widths

see more bands, more receivers + Extremely high dynamic range: operate in worst

conditions + Extreme flexibility through reprogrammability (ultimate

SDR): future benefits – Technically challenging to design

Example Third Generation SDR Architecture

dd

7.9Gbps + 1Gbps

F A T

“Our Choices Determine Our Destiny” — A.R. Benard

Shortcut to the finish line:

Direct Sampling Receiver A

PowerSDR et. al.

Rapidly bring up a direct sampling receiver

Each 192kHz receiver uses 10+ Mbps

A full 1MHz of bandwidth panadapter: 73 Mbps

Not scalable

DAY

TON

201

2

“Our Choices Determine Our Destiny” — A.R. Benard

Building for the future:

FLEX-6000 SmartSDR

New software, much more work in the radio

A full-screen panadapter: <1 Mbps AT ANY WIDTH

Scalable, Remotable

DAY

TON

201

2

Spectrum Display BW

1MHz <500kbps

1MHz 77Mbps

150:1 Bandwidth Difference

10MHz <500kbps

1500:1 Bandwidth Difference

10MHz 770Mbps

SmartSDR APIs

FLEX-6XXX

Windows Computer

UDP TCP

FlexLib

SmartSDR Ethernet API

SmartSDR FlexLib API

SmartSDR

SmartSDR-Windows

© 2 0 1 5 F L E X R A D I O S Y S T E M S

Continued to hear that knobs/buttons are important Often, existing products maligned for complexity Station reconfiguration time frustrating Integration in SO2R, M/1, M/2, M/M stations a problem The dream of simple remote operation…

Maestro The interviews…


Maestro Control surface and more…


Maestro Control surface and more

Essentially a remotable SmartSDRwith knobs & buttons Can be used in place of a computer to run any FLEX-6000 Optimized to have just frequently used controls Let’s take a closer look …


Maestro Display

WXGA (1280x800) 8” IPS Cap Touch Can show one or two panafalls Up to two slices Cap touch, pinch to zoom, buttons and pop-up menus Built on SmartSDR API


Maestro Controls

Slice A

Slice B or

RIT/XIT


Maestro Capabilities

Integrated CW keyer Mic, headphones, line in/out ~6 hours of battery life or plug-in (12V nom.) WiFi (802.11 a/b/g/n) and wired Ethernet (1GbE) VESA mount for Public Safety comms, mobile use, etc


Maestro What’s next?

Control of a computer and large display (fairly easy) Multiple Maestros on a single radio WAN use (away from the shack) Who knows …

SmartSDR v1.3 August 2014

CWX Transverter operation Contest Logger return focus Profile manager Diversity

SmartSDR v1.3.8 October 2014

Mostly fixes from v1.3.0 Sharper panafall lines lines

SmartSDR v1.4 March 2015

LAN Remote FM / DFM Memories Performance Optimizations CW Enhancements DAX Enhancements CAT Improvements

SmartSDR v1.4.3 April 2015

Binaural receive Digital transmit monitor TX Audio play/record FlexControl Enhancements

SmartSDR v1.4.11 May 2015

ATU Memories First noise mitigation work (NR & ANF)

Current Software Priorities

Noise Blanker DXing and Contesting Maestro v2.0

TX6G: A Picture is worth 1,000 words

DXing and Contesting

Focus Return for loggers SO2R Integration (N1MM) SO2R in a single radio ! FlexRadio Systems 1.5kW Solid State Amplifier

Other Presentations Today

1300 Contest Luncheon, Grokking HF Receiver Performance (Room 9) 1400 SmartSDR API and applications (Room 3)