Software Defined Receiver (SDR): A Hardware and Software Primer

Transcription

1 Software Defined Receiver (SDR): A Hardware and Software Primer Mark J Culross, KD5RXT Page 1 of 32

2 Today s topics An SDR Primer Topics Defining Software Defined Receiver (SDR) General overview of SDR A sampling of SDR hardware A sampling of SDR software Use & features of the SDR-RADIO application Useful links Live SDR Demo Page 2 of 32

3 SDR the definition According to Wikipedia, a Software Defined Receiver (actually, more generically, a Software Defined Radio) is: A software-defined radio system, or SDR, is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which used to be only theoretically possible. A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the generalpurpose processor, rather than being done in special-purpose hardware. Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used. [ ] Page 3 of 32

4 SDR so, what is it really (math UGHHH)?? General SDR overview Goal: convert RF to audio Take advantage of traditional frequency mixing, but not for traditional IF conversion F1 X F2 results in Sum of frequencies ( F1 + F2 ) and ( ( -F1 ) + ( -F2 ) ) Difference of frequencies ( F1 - F2 ) and ( F2 F1 ) Quadrature mixing Delay RF carrier frequency by 90 (Q) Use with in-phase signal (I) Combine the two streams together to compute Amplitude: m t = I 2 t + Q 2 t Phase: Ø t = tan -1 (Q t / I t ) Use PC soundcard to sample & process I & Q streams (gooey magic!!) FFT (fast Fourier transform) Convert complex I & Q data into frequency domain Output is approximately equal to a large bank of narrow bandpass filters (bins) Each bin measures the spectrum energy within its respective bandwidth Allows demodulation of standard signals such as AM, FM, FMstereo, QPSK, BPSK, SSB, CW, QAM, OFDM, DSB, DRM, etc. See Richard B Langley s excellent treatise on this at the following URL: Page 4 of 32

5 What do I currently own/use?? RTL TV301 Dongle (Elonics E4000 tuner) ezcap USB 2.0 DVB-T/DAB/FM dongle RTL Dongle (Elonics E4000 tuner) Terratec NOXON DAB/DAB+ USB dongle (rev 2) FUNcube Dongle Pro (original) FUNcube Dongle Pro Plus RFspace SDR-IQ An SDR Primer A Sampling of Hardware Page 5 of 32

6 RTL Asian/European TV Receiver Page 6 of 32

7 RTL Asian/European TV Receiver RTL2832U generic TV receivers Many designed around an Elonics E4000 set-top box TV tuner chip Spec d for 64MHz-1700MHz (VHF/UHF) Most chips will work from just over 51MHz to upwards of 2200MHz Includes an L-band gap from 1100MHz-1250MHz (NOTE: this is a limitation of the E4000 tuner) NOTE: these units come with a PAL connector, which I replaced with an SMA Requires additional Windows drivers Easiest to get Zadig hardware driver installation package Pay attention: specific versions (e.g. WinXP vs. others) Compatible with existing SDR software May need custom DLL added for some SDR software packages >2MHz sampling rate results in 2MHz useable bandwidth all at once Can record full BW I&Q data streams for post-processing Currently available for $20-35 US from many different suppliers RTL2832U-E4000-Tuner-PAL- / ?pt=LH_DefaultDomain_0&hash=item2578be90b1 Page 7 of 32

8 FUNcube Dongle Pro Page 8 of 32

9 FUNcube Dongle Pro FUNcube Dongle Pro (original) design Designed and produced by Howard Long, G6LVB Designed around an Elonics E4000 set-top box TV tuner chip (under NDA) Spec d for 64MHz-1700MHz (VHF/UHF) Most chips will work from just over 51MHz to upwards of 2200MHz Includes an L-band gap from 1100MHz-1250MHz (NOTE: this is a limitation of the E4000 tuner) Designed to use HID USB interface & USB 1.0 audio interface, both natively built into Windows No additional drivers required!! Compatible with existing SDR software May need custom DLL added for some SDR software packages 96kHz sampling rate results in 80kHz useable bandwidth all at once Can record full BW I&Q data streams for post-processing Was approximately $ US Currently no longer in production due to unavailability of E4000 tuner chip Page 9 of 32

10 FUNcube Dongle Pro Plus Page 10 of 32

11 FUNcube Dongle Pro Plus FUNcube Dongle Pro Plus design Just like the original, designed and produced by Howard Long, G6LVB Designed around another set-top box TV tuner chip (under NDA) Spec d for 150kHz-1900MHz (HF/VHF/UHF) Most chips will work from 150kHz to upwards of 2050MHz Includes a gap from 240MHz-420MHz (NOTE: once again, this is a limitation of the tuner chip) Just like the original, designed to use HID USB interface & USB 1.0 audio interface, both natively built into Windows No additional drivers required!! Just like the original, compatible with existing SDR software May need custom DLL added for some SDR software packages 192kHz sampling rate results in 170kHz useable bandwidth all at once Can record full BW I&Q data streams for post-processing Currently approximately $ US Page 11 of 32

12 RFspace SDR-IQ Page 12 of 32

13 RFspace SDR-IQ RFspace SDR-IQ Spec d for 500Hz-30MHz (HF only) in 1Hz steps Designed to use USB 2.0 audio interface, natively built into Windows No additional drivers required!! Compatible with existing SDR software 196kHz sampling rate results in 190kHz useable bandwidth all at once Can record full BW I&Q data streams for post-processing Includes filtering for excellent balance & high-quality HF reception Currently approximately $ US Page 13 of 32

14 A Sampling of Software Some popular & readily available software you can use with your SDR hardware SpectraVue SDR# HDSDR Simon Brown s (HB9DRV) SDR-radio (V2) IMHO, this software beats the pants off of all others hands-down, with feature-rich capabilities Page 14 of 32

15 Major features of SDR-radio SDR-radio (V2) features Input source selection More control panel Frequency explorer Band selection Mode selection RX filter selection Noise filters Multiple VFOs Audio spectrum Recording & playback Page 15 of 32

16 Major features of SDR-radio Page 16 of 32

17 Major features of SDR-radio Page 17 of 32

18 Major features of SDR-radio Page 18 of 32

19 Major features of SDR-radio Page 19 of 32

20 Major features of SDR-radio Page 20 of 32

21 Major features of SDR-radio Page 21 of 32

22 Major features of SDR-radio Page 22 of 32

23 Major features of SDR-radio Page 23 of 32

24 Major features of SDR-radio Page 24 of 32

25 Major features of SDR-radio Page 25 of 32

26 Major features of SDR-radio Page 26 of 32

27 Major features of SDR-radio Page 27 of 32

28 Major features of SDR-radio Page 28 of 32

29 Major features of SDR-radio Page 29 of 32

30 Links Useful links Information on RTL receivers in general Information on FUNcube Dongle Pro (original) Information on FUNcube Dongle Pro Plus Information on RFspace SDR-IQ Information on SpectraVue Information on SDR# Information on HDSDR Information on SDR-console (V2) [ use the download link under Beta Kits, NOT the Download Now button (which is a 3 rd -party link for 7-Zip!!) ] Page 30 of 32

31 Live SDR Demo Page 31 of 32

32 Parting words... Thank-you for attending this presentation Feel free to contact me at with any questions at any time Contact me at for copies of this presentation Include your preferred snail mail address for where I should send the CD Mark J Culross, KD5RXT Page 32 of 32