Spectrum Monitoring and Interference Analysis Using NI PXI

Author(s):
Jim West - Summitek Instruments
Jim Pierson - Summitek Instruments

Industry:
Telecommunications

Products:
LabVIEW, RF, PXI/CompactPCI,

The Challenge:
Increasing the functionality and expandability of a spectrum analyzer for improved RF environment monitoring and interference management.

The Solution:
Pairing National Instruments PXI hardware with the OASIS spectrum monitoring package to deploy multiple spectrum analyzers with high throughput and improved service.

Interference is becoming more prevalent in the wireless community with the increasing number of transmitters coming on the air. Wireless service providers have traditionally used spectrum analyzers to monitor their channels and frequencies and the adjacent spectrum and to locate sources of interference. Unfortunately, a spectrum analyzer can only show the interfering signal to the user, who must then determine the source of the interference. To solve interference problems, the user must understand the RF environment, know which transmitters are operating nearby, and identify any new or unlicensed emitters.

We identified the National Instruments PXI-5660 RF Vector Signal Analyzer and the NI PXI-5690 RF Preamplifier as the ideal hardware combination to pair with our OASIS spectrum monitoring package. The PXI form factor allows us to deploy multiple spectrum analyzers within the same compact space as a single benchtop spectrum analyzer. Plus, the NI PXI-5660 offers higher data throughput and comparable specifications to traditional spectrum analyzers.

OASIS requires no software development and extends the capabilities of the PXI-5660 by letting the user view multiple frequency ranges simultaneously, or in the case of multiple vector signal analyzers, remotely control the instruments with a single user interface.

The system has an extensive set of tools that automatically characterize an RF environment and compare the actual environment to a database of known emitters. It then constructs a database by monitoring the local RF environment or by accessing a database of FCC-licensed emitters in the United States. Users simply enter the frequencies being affected by interference, and the system generates a list of the suspect emitters in the area that could be causing the interference. The PXI-5660 then tests the suspect emitters. This solution reduces the amount of time spent in the field and provides reports that can be used to prove interference.

The PXI-5660 and OASIS combination provides data to support spectrum management processes through archival data storage, unattended and remote operation, and data post-processing. It also helps ensure compliance with spectrum regulations by quickly identifying licensed and unlicensed emitters, and by tracking noncompliant transmitters with emission masks and limits. This solution provides an easy, economical way to identify sources of interference, find rogue emitters, and manage spectral usage efficiency from channel occupancy statistics, helping to ensure quality of service and network reliability.

The complete hardware and software solution is more efficient and economical than most benchtop spectrum analyzers alone. The off-the-shelf system is highly functional, and requires no software development. Users can record and view multiple frequency bands on a single NI PXI-5660 to quickly resolve interference issues. The system also performs unattended data logging for hours, days, or even weeks for later analysis, further reducing time spent in the field. Users can also save time and money by remotely monitoring test locations and changing test scenarios over an Ethernet connection, eliminating the need to travel to and from test locations.

With the logging capability, users can collect data and essentially perform unattended spectrum monitoring, capturing and storing the spectral data to perform other tasks instead of spending time watching a display. By logging data, the operator can see not only the event of interest, but also the spectral data before and after the event.

Using OASIS with the NI PXI-5660 is an excellent off-the-shelf solution for customers who need a spectrum monitoring solution but do not want to spend the time developing their own code. Users save time and development costs while maintaining flexibility for future development of custom applications using National Instruments LabVIEW.

The system also allows remote control and data collection. Users can set up the NI PXI-5660 at essentially any remote location, and use an Ethernet TCP/IP connection to remotely control and collect data from the instrument, eliminating travel time and cost. With this solution, users can control up to four NI PXI-5660 instruments remotely and display their data simultaneously. These instruments can be in the same PXI chassis or they can be distributed at different locations. With this flexibility, users can control multiple instruments remotely, and set up a network of monitoring locations if need be.

 

For more information, contact:

Jim Pierson

Summitek Instruments

Tel: (303) 768-8080

Fax: (303) 768-8181

E-mail: jimp@summitekinstruments.com

 

 

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