Global Navigation Satellite Systems (GNSS)

GNSS is a generic term for Satellite Navigation Systems. Using existing and planned GPS capabilities and other satellite systems such as Europe’s Galilleo, Russia’s GLONASS and China’s Compass/Beidou, GNSS provides precise global positioning

GPS has used the L1 band at 1575.42MHz and the “Military” L2 band at 1227.60MHz. A new L5 band will be operated at 1176.45MHz as well as a second civilian signal known as L2C. The new civil L5 signal is geared specifically for safety and aviation use. L5 and L2C combined with L1 introduce triple-frequency GPS capability, enhancing the robustness of service and enabling new techniques for high accuracy positioning. It is likely that the L5 band will be used in applications beyond its initial intended use.

In the long term, all available signals will be used for Position, Navigation and Timing calculations to improve position accuracy to the cm range. Evolved GNSS receivers will combine the new L5 band and other GNSS signals from Galileo, Compass and GLONASS with traditional L1 and L2 to support new applications and enhanced coverage.

Next generation GNSS receivers will need to receive multiple signals from 4 or more satellites (typically 12 to 20) AND tune to at least three channel frequencies (L1, L2, and L5).

Simultaneous reception of multiple bands from multiple satellite systems AND the flexibility to selectively receive specific signals is crucial.

RF Integration’s L1 band GNSS RF IP Core (see diagram) serves existing and planned Military and Commercial GNSS applications.

Mobile/Handheld

Mobile phones support the C/A code at the GPS L1 frequency of 1575.42MHz. Adding signals at L1C, L2C and L5 bands together with Compass, Galileo and GLONASS signals will provide improved performance.

Remote Coverage

Using signals from L1, L2 and L5 bands with signals from Compass, Galileo and GLONASS enhances position accuracy in areas where Network Assistance, map matching or terrestrial sources are not available.

Military GPS

Satellite Navigation allows precise delivery of Smart Munitions and allows forces to locate themselves more easily. GPS system upgrades such as SAASM and M-code continue to make GPS indispensable.

Precision Measurement

Augmented by terrestrial signals, GNSS accuracy can improve to the cm range. As additional bands and satellite signals become available, applications like Precision Agriculture will continue to thrive.

Automotive

GPS is the basis of precise vehicle navigation systems. Automotive GPS requires higher reliability and connections to Inertial Sensors or CAN-based vehicle networks. Additional signals enhance performance.

Next Generation GNSS RF Solutions

GNSS applications require a wide band RF front end with significant programmability to accept or reject various GNSS signals. As a minimum, this Universal RF front end should be capable of handling the new L5 GPS band at 1176.45MHz as well as the E6 Galileo band at 1278.75MHz. It should have the ability to program IF filter cut off frequency and suppression. A/D converters with user selectable sampling rates are needed. The universal front end should also be capable of interfacing to a wide range of digital IC’s. See chart

GNSS signals can grouped into low band (1100-1290MHz) and high band (1550-1650MHz.) The signals are received at an exceptionally low level and require amplification of 90dB or more before they can be converted from analog to digital form. Care must be taken to ensure that these signals are not jammed by unintentional or hostile jammers or even signals generated in the GNSS receiving equipment.

Next generation GNSS receivers will need to receive multiple signals from 4 or more satellites (typically 12 to 20) AND tune to at least three channel frequencies (L1, L2, and L5).

Simultaneous reception of multiple bands from multiple satellite systems AND the flexibility to selectively receive specific signals is crucial.