source:truck tracking webfleet solutions release time:2022-12-02 Hits: Popular:realtime gps tracker online
In the design of GPS antenna unit, high-frequency and low-noise amplifiers are used to reduce the thermal noise of GPS antenna and the influence of the previous unit circuits on the receiver performance; When using GPS satellite to achieve navigation and positioning in the principle of GPS antenna, the main task of the user receiver is to extract pseudo-random noise code and data code from the satellite signal, so as to further calculate the position, speed and time (PVT) and other navigation information of the receiver carrier. Therefore, GPS receiver is a crucial user equipment.
At present, the practical GPS receiver circuit is generally composed of antenna unit, RF unit, communication unit and reconciliation unit. Based on the analysis of GPS satellite signal composition, this paper gives the principle and application of RF front-end GP2010.
1、 Composition of GPS satellite signal
GPS satellite signal is synthesized by typical code division multiple access (CDMA) modulation technology. Its complete signal mainly includes carrier, pseudo-random code and data code. The signal carrier is in the L-band, and the center frequencies of the two carriers are recorded as L1 and L2 respectively. The reference clock frequency f0 of satellite signal is 10.23MHz, and the center frequency of signal carrier L1 is 154 times of f0, namely:
fL1=154 × f0=1575.42MHz (1)
Its wavelength λ 1=19.03cm; The center frequency of signal carrier L2 is 120 times of f0, namely:
fL2=120 × f0=1227.60MHz (2)
2、 Analysis of GPS antenna principle
Its wavelength λ 2=24.42cm。 The frequency difference between the two carriers is 347.82MHz, which is about 28.3% of L2. In this way, the carrier frequency can be selected to measure or eliminate the propagation delay error caused by the ionosphere effect when the navigation signal propagates from the GPS satellite to the receiver. Pseudo random noise code (PRN), namely ranging code, mainly includes precise ranging code (P code) and coarse ranging code (C/A code). The code rate of P code is 10.23MHz, and that of C/A code is 1.023MHz. Data code is the navigation and positioning data sent by GPS satellite to user receiver in binary form, also called navigation message or D code, which mainly includes satellite calendar, satellite clock correction, ionospheric delay correction, working state information, information of C/A code conversion to captured P code and general ephemeris of all satellites; The total message consists of 1500 bits and is divided into 5 subframes. Each subframe transmits 10 words within 6s, 30 bits for each word, totaling 300 bits. Therefore, the baud rate of the data code is 50bps.
Read recommendations:
Special Looks GPS Tracker PCBA
TK200AM-Disposable GPS Tracker
International requirements aircraft must be equipped with GPS
Next article:Smartphone GPS, everywhere
Related Information
gps tracker no monthly fee
2023-04-11car gps tracker distributors
2023-04-23pet gps tracker cat wholesaler
2023-03-16fleet gps tracking distributors
2023-04-23Dog gps tracker manufacturer
2023-04-23gps vehicle tracker wholesale
2023-04-23fleet management software webfleet solutions
2023-03-16Fleet management expert
2023-03-16gps tracker for kids
2023-04-11gps tracker for Car
2023-04-11G01 Smallest Personal Old People Mini GPS Tracker for Kids
2022-06-19TK08A Motorcycle GPS Tracker
2022-06-20NB20 -4G Bluetooth Smart Pet Tracker
2022-06-21G08L - 4inch Smart Tail Light Tracker
2022-06-20P60L Personal gps tracker
2022-06-21GPS application in ionospheric monitoring
2022-07-28The advantage of remote anti -theft of electric vehicle GPS positioner.vehicle gps tracker webfleet
2023-03-28What are the built -in cards usually use in the car GPS positioner?gps tracker no monthly fee Manufa
2023-03-28Why is it recommended to install the GPS vehicle positioning system?Portable car gps systems
2023-03-24GPS Beidou timing service accuracy can reach 10 nanoseconds
2022-08-11Application of GPS
2022-09-24GPS death phenomenon
2022-09-14Brief introduction of GPS control part
2022-09-22GPS receiver product.Magnetic gps tracker wholesale
2023-06-05GPS guidance (Bearing)
2022-11-23Gps speed limiter.What should be paid attention to when installing GPS locators on rental company ve
2023-10-20Compared to the advantages of GPS car navigation and mobile phone navigation.GPS Tracker for vehicle
2023-05-09The prototype of the third generation GPS system GPS Blokc III starts testing
2022-12-06Scope of GPS.plug & play Obd gps tracker Vendor
2023-09-09GPS Development.cat gps tracker manufacture
2023-07-20