© 2005, it - instituto de telecomunicações. Todos os direitos reservados. David Ferreira, DL-IT Rafael Caldeirinha, DL-IT | IPL Development and Performance Assessment of a Real Time High-Resolution RF Channel Sounder IGARSS 2011 Vancouver – 29 th July 2011

2 O UTLINE Motivation and objectives Sliding correlation principle Implemented sounder topology Performance assessment System photos Conclusions and further work IGARSS 2011 | Vancouver – 29 th July 2011

3 M OTIVATION Characterisation and modelling of radiowave propagation in doubly selective channels. IGARSS 2011 | Vancouver – 29 th July 2011

4 O BJECTIVES Design, implementation and test of a Swept Time-Delayed Cross- Correlation (STDCC) RF channel sounder. Ease in adjusting key sounder parameters allowing to maximise its performance depending on the measurement scenario; High time resolution of the channel impulse responses (2ns); Ensure a good overall dynamic range; Capability to measure multipath components in both amplitude and phase, allowing for Doppler spectrum analysis with post-processing. IGARSS 2011 | Vancouver – 29 th July 2011

5 S LIDING CORRELATION PRINCIPLE (1/4) Typical transmitter section Typical receiver section IGARSS 2011 | Vancouver – 29 th July 2011

6 S LIDING CORRELATION PRINCIPLE (2/4) PN sequence generator Auto-correlation of a PN sequence Real spectrum of a PN sequence at 500MHz IGARSS 2011 | Vancouver – 29 th July 2011

7 S LIDING CORRELATION PRINCIPLE (3/4) IGARSS 2011 | Vancouver – 29 th July 2011

8 S LIDING CORRELATION PRINCIPLE (4/4) IGARSS 2011 | Vancouver – 29 th July 2011

9 I MPLEMENTED SOUNDER TOPOLOGY T RANSMITTER BLOCK IGARSS 2011 | Vancouver – 29 th July 2011

10 I MPLEMENTED SOUNDER TOPOLOGY T RANSMITTER BLOCK RF2052 development board Frequency range: 300MHz to 2.4GHz Resolution: 0.596Hz IGARSS 2011 | Vancouver – 29 th July 2011

11 I MPLEMENTED SOUNDER TOPOLOGY T RANSMITTER BLOCK DPG2 and AD9739EBZ boards Sampling frequency: 2500MSPS 14 bits resolution IGARSS 2011 | Vancouver – 29 th July 2011

12 I MPLEMENTED SOUNDER TOPOLOGY R ECEIVER BLOCK IGARSS 2011 | Vancouver – 29 th July 2011

13 I MPLEMENTED SOUNDER TOPOLOGY R ECEIVER BLOCK 6GHz Mixer – DM0408LW2 RF/LO Bands: 4 to 8 GHz; IF Band: DC to 2GHz; Losses: 5dB IGARSS 2011 | Vancouver – 29 th July 2011

14 I MPLEMENTED SOUNDER TOPOLOGY R ECEIVER BLOCK I/Q Downconverter – HMC-C009 RF/LO Bands: 4 to 8.5 GHz; IF Band: DC to 3.5GHz; Losses: 9dB IGARSS 2011 | Vancouver – 29 th July 2011

15 I MPLEMENTED SOUNDER TOPOLOGY R ECEIVER BLOCK Correlation Mixer – ZFM-2-S+ RF/LO Bands: 1 to 1000 MHz; IF Bands: DC to 1GHz; Losses: 6dB IGARSS 2011 | Vancouver – 29 th July 2011

16 IF P ERFORMANCE ASSESSMENT T EST CONFIGURATION Possibility to change the cable lengths, therefore the time delay associated to each multipath component; Possibility to adjust the losses associated to each path. IGARSS 2011 | Vancouver – 29 th July 2011

17 IF P ERFORMANCE ASSESSMENT S OUNDER PARAMETERS IGARSS 2011 | Vancouver – 29 th July 2011

18 IF P ERFORMANCE ASSESSMENT The system is able to distinguish multipath components separated by approximately 2ns. R ESULTS (1/2) IGARSS 2011 | Vancouver – 29 th July 2011

19 Assessment of the dynamic range. R ESULTS (2/2) IGARSS 2011 | Vancouver – 29 th July 2011 IF P ERFORMANCE ASSESSMENT

20 RF P ERFORMANCE ASSESSMENT T EST CONFIGURATION Using the same sounder parameters as in the IF bench test. IGARSS 2011 | Vancouver – 29 th July 2011

21 RF P ERFORMANCE ASSESSMENT The figure shows two components which correspond to the periodic repetition of the sequence. R ESULTS (1/2) IGARSS 2011 | Vancouver – 29 th July 2011

22 RF P ERFORMANCE ASSESSMENT The figures show preliminary results of Doppler measurements at 18.7GHz. R ESULTS (2/2) IGARSS 2011 | Vancouver – 29 th July 2011

23 IGARSS 2011 | Vancouver – 29 th July 2011 S YSTEM PHOTOS IF-S TAGE (1/2)

24 IGARSS 2011 | Vancouver – 29 th July 2011 IF-S TAGE (2/2) S YSTEM PHOTOS

25 IGARSS 2011 | Vancouver – 29 th July 2011 S YSTEM PHOTOS RF-S TAGE (1/2)

26 IGARSS 2011 | Vancouver – 29 th July 2011 S YSTEM PHOTOS RF-S TAGE (2/2)

27 IGARSS 2011 | Vancouver – 29 th July 2011 S YSTEM PHOTOS D OPPLER MEASUREMENT

28 C ONCLUSIONS The developed IF system can successfully distinguish multipath components separated by only 2ns and has a dynamic range around 50dB. Despite the limitations caused by an RF faulty component, preliminary tests, both in bench as well in an anechoic chamber, show an overall dynamic range for the complete system (IF+RF) of close to 40dB. By allowing an easy adjustment of the PN sequence properties, either in its length or chip rate, one can adjust the sounder specifications (e.g. dynamic range, time and Doppler resolutions, etc.) to the measurement scenario/geometry. IGARSS 2011 | Vancouver – 29 th July 2011

29 F URTHER WORK Integration of the developed IF stage on other RF front-ends, namely (37, 60 and 300 GHz), allowing for high scalability. Acquisition of a better data acquisition card, in order to improve the maximum detectable object speed through Doppler analysis of the measured PDP (currently limited to a maximum of 120Hz for a maximum discernible delay of 255ns). Housing of the developed IF stage allowing for an easy relocation of the equipment over different measurement locations. IGARSS 2011 | Vancouver – 29 th July 2011

© 2005, it - instituto de telecomunicações. Todos os direitos reservados. Thank you. IGARSS 2011 Vancouver – 29 th July 2011 Development and Performance Assessment of a Real Time High-Resolution RF Channel Sounder s: