CityScape Project – Spectrum Plots

Below are some sample p.s.d estimate data collected using Philadelphia CityScape stations.

LTE Band 17 Downlink (709MHz) Spectrogram

(*This data is collected by running custom scripts on the stations, not using the default CityScape collection software.)

Collection Time

  • 2017-09-12 17:17 – 18:17 (UTC) (1:17 – 2:17pm EDT)

Data Structure

  • 703.96 – 714.04 MHz, 180 kHz resolution PSD estimates; total 56 FFT points. Max-held (instead of time averaging).

    • The first ‘PSD bin’ is from 703.96MHz to 704.14MHz, the second ‘PSD bin’ is from 704.14MHz to 704.32MHz, and so on..

Sensor configuration

  • Location: Graduate Research Wing Rooftop, 200 South 3rd street, Philadelphia, PA 19104, United States.

  • Hardware: USRP N200 + UBX40 daughterboard, connected to wideband discone antennas. Calibrated to provide dBm readings (roughly).

  • Rx Amplifier Gain: 0dB

  • Antenna Port: TX/RX (a wideband discone antenna attached).

  • Sampling Rate (after decimation): 12.5MS/s

  • (DSP-level) Intermediate Frequency: -12.5 MHz

  • Noise figure: approx 25.5dB (relatively high, due to the maximum achievable gain without overloading the RF frontend).

TV(ATSC) P.S.D Estimates – Philadelphia

This is generated using the standard CityScape station software and Octave (free Matlab alternative).

Collection Time

  • 2017-07-14 12:00 – 13:00 (UTC)

Data Structure

  • 512 – 608MHz PSD estimates, min/max/avg.

Sensor configuration

  • Location: Graduate Research Wing Rooftop, 200 South 3rd street, Philadelphia, PA 19104, United States.

  • Hardware: USRP N200 + UBX40 daughterboard, connected to wideband discone antennas. Calibrated to provide dBm readings (roughly).

  • Rx Amplifier Gain: 0dB

  • Antenna Port: RX2 (a wideband discone antenna attached).

  • Sampling Rate (after decimation): 25MS/s

  • (DSP-level) Intermediate Frequency: 0 Hz

Data File (Matlab-comaptible)

Download

TV(ATSC) P.S.D Estimates – University of Washington

This is generated using the standard CityScape station software and Octave (free Matlab alternative). For comparison, data collected using a Keysight spectrum analyzer (FieldFox) is also shown.

Collection Time

Cityscape

  • 2017-07-10 5:00 – 6:00 (UTC)

Keysight FieldFox

  • 2017-07-10 8:00 – 10:00 (UTC)

Data Structure

  • 512 – 608MHz PSD estimates, min/max/avg.

Sensor configuration

Cityscape

  • Location: 3960 Benton Lane NE, Sieg Hall (rooftop), University of Washington, Seattle, WA 98195

  • Hardware: USRP N200 + UBX40 daughterboard, connected to wideband discone antennas. Calibrated to provide dBm readings (roughly).

  • Rx Amplifier Gain: 0dB

  • Antenna Port: RX2 (a wideband discone antenna attached).

  • Sampling Rate (after decimation): 25MS/s

  • (DSP-level) Intermediate Frequency: 0 Hz

Keysight FieldFox

  • Sensor: Agilent(Keysight) FieldFox N9914A, spectrum analyzer mode.
  • Attenuation : 0dB; Pre-amplifer: off
  • Antenna Port #2
  • Resolution Bandwidth: 20 kHz
  • 100 averages.

Data File (Matlab-comaptible)

Cityscape

Keysight FieldFox

Note

*CityScape stations gave better noise floor in this case, but also more spurious signals. Both Keysight FieldFox and Cityscape stations quickly overloaded when the gain level of the preamp are increased (due to the strong wideband RF energy coming from the outdoor discone antenna).