Tag: LTE signals

  • Tallysman offers embedded triple-band GNSS antenna

    Tallysman offers embedded triple-band GNSS antenna

    Tallysman Wireless Inc. has added the low-profile triple-band HC997EXF to its line of embedded helical GNSS antennas, and the TWA928LXF to its AccuAuto line. Both feature the company’s eXtended Filtering (XF).

    Designed for UAVs and Other Applications

    Photo: Tallysman
    Photo: Tallysman

    The HC997EXF is designed for precise positioning, covering the GPS/QZSS-L1/L2/L5, GLONASS-G1/G2/G3, Galileo-E1/E5a/E5b, BeiDou-B1/B2/B2a, and NavIC-L5 frequency bands. It also covers the satellite-based augmentation system (SBAS) available in the region of operation — WAAS (North America), EGNOS (Europe), MSAS (Japan) or GAGAN(India) — as well as L-band correction services.

    The low-profile helical antenna is packaged in a light (11 g) and compact form factor (60 mm wide and 25 mm tall). Its precision-tuned, high-accuracy helical element provides an excellent axial ratio and operates without a ground plane. These features make the HC997EXF suitable for lightweight unmanned aerial vehicle (UAV) navigation and a wide variety of precision applications.

    The HC997EXF antenna base has a flying lead and a variety of connectors. To facilitate installation, Tallysman provides an optional embedded helical mounting ring that traps the outer edge of the antenna circuit board to the host circuit board or any flat surface. Tallysman provides support for installation and integration of its embedded helical antennas to ensure optimal performance.

    New Vehicle Antenna Launched

    Photo: Tallysman
    Photo: Tallysman

    Another new XF antenna, the TWA928LXF, is part of Tallysman’s  AccuAuto autonomous vehicle family of compact and rugged embedded antennas.

    The triple-band TWA928LXF supports GPS/QZSS-L1/L2/L5, GLONASS-G1/G2/G3, Galileo-E1/E5a/E5b, BeiDou-B1/B2/B2a, and NavIC-L5 signals and frequency bands, including L-band correction services.

    The TWA928LXF vehicle antenna features a patented Tallysman Accutenna technology antenna element, an integrated ground plane, radome and underside cover that provides mist and condensation protection. The bottom cover also supports the antenna cable and mitigates cable vibration to ensure that the antenna has a long service life, while the ground plane improves antenna performance.

    All AccuAuto antennas are built with Automotive Electronics Council (AEC) certified electronic components designed to perform under the most challenging environmental conditions, such as extreme temperatures, shock and vibration.

    XF Coming to All Lines

    eXtended Filtering enables the HC997EXF antenna to mitigate new and existing radio frequency bands that interfere with GNSS signals. The custom XF filtering has been tested to mitigate new (Europe and Japan) and existing LTE signals, enabling the XF antennas to produce clean and pure GNSS radio frequency data.

    For example, in North America, the planned Ligado service, which will broadcast in the frequency range of 1526 to 1536 MHz, could affect GNSS antennas that receive space-based L-band correction service signals (1539–1559 MHz).

    Similarly, LTE signals or their harmonics, such as the new LTE bands in Europe–Band 32 (1452–1496 MHz)–and Japan–Bands 11 and 21 (1476–1511 MHz)–have affected GNSS antennas and receivers.

    Lastly, the Inmarsat satellite communication uplink (1626.5–1660.5 MHz), commonly used on maritime vessels, can also affect nearby GNSS antennas.

    Tallysman Wireless also has added eXtended Filtering (XF) to its TW3800 series of Accutenna precision antennas, and will be rolled out to all of Tallysman’s product lines.

  • Tallysman adds eXtended Filtering to TW3900 accutenna antennas

    Tallysman adds eXtended Filtering to TW3900 accutenna antennas

    The TW3967-XF antenna. (Photo: Tallysman)
    The TW3967-XF antenna. (Photo: Tallysman)

    Tallysman Wireless has added new eXtended Filtering (XF) features to the TW3900 series of Accuntena precision antennas. Tallysman designed the XF feature to mitigate interference from all near-band signals and ensure that the antenna provides the purest GNSS signals.

    Tallysman’s TW3972XF, TW3972EXF, TW3972LGXF, TW3967XF, and TW3967LGXF are triple-band antennas that support GPS/QZSS (L1/L2/L5), GLONASS (G1/G2/G3), Galileo (E1/E5ab), BeiDou (B1/B2/B2a), NavIC L5, and L-Band correction services.

    Worldwide, the radio frequency spectrum has become congested as many new LTE bands have been activated, and their signals or harmonic frequencies can affect GNSS antennas and receivers. In North America, the planned Ligado service, which will broadcast in the frequency range of 1526 to 1536 MHz, can affect GNSS antennas that receive space-based L-band correction service signals (1539–1559 MHz).

    The TW3972-XF antenna. (Photo: Tallysman)
    The TW3972-XF antenna. (Photo: Tallysman)

    New LTE signals in Europe [Band 32 (1452–1496 MHz)] and Japan [Bands 11 and 21 (1476–1511 MHz)] have also affected GNSS signals. Lastly, the Inmarsat satellite communication uplink (1626.5–1660.5 MHz) commonly used on maritime vessels can also affect nearby GNSS antennas.

    Tallysman’s custom XF filtering has been tested to mitigate new (Europe and Japan) and existing LTE signals, enabling the XF antennas to produce clean and pure GNSS radio frequency data. The deep XF filter technology will be applied to all of Tallysman’s product lines.

  • Research Online: A way to monitor LTE signals for autonomous vehicles

    Integrity Monitoring of LTE Signals of Opportunity-Based Navigation for Autonomous Ground Vehicles

    By Mahdi Maaref, Joe Khalife and Zak M. Kassas/University of California, Riverside

    FIGURE 1. RAIM framework for LTE-based navigation without GNSS signals. (Images: Authors)
    FIGURE 1. RAIM framework for LTE-based navigation without GNSS signals. (Images: Authors)

    Proprietary receivers and navigation frameworks for autonomous ground vehicle (AGV) navigation with long-term evolution (LTE) cellular signals demonstrate meter-level accuracy with standalone LTE signals and lane-level accuracy with LTE signals coupled with other sensors (inertial and lidar).

    As the number of systems that rely on cellular signals for navigation grows, the need for monitoring the integrity of their navigation solution becomes essential.

    This paper proposes a receiver autonomous integrity monitoring (RAIM) framework for AGV navigation with LTE signals of opportunity. Experimental results evaluate the efficacy and accuracy of the proposed RAIM-based fault detection and exclusion technique, demonstrating a reduction of 22% in the position root-mean-squared error (RMSE).

    FIGURE 1 demonstrates the RAIM framework: (a) When GNSS signals are unusable, LTE signals are used for navigation and integrity measures are calculated; (b) simulation results of downtown Riverside, California, where the black regions represent areas where multipath is expected to exceed 0.5 meters; (c) experimental setup; (d) environment and location of LTE towers; and (e) experimental results showing severe multipath being autonomously detected and excluded.

    The estimation error represents the difference between the ground truth from an RTK GNSS-IMU system and our LTE-IMU system.

    More information available via www.aspin.ucr.edu and www.ion.org/publications/browse.cfm.