The correlator in a GPS receiver is used to, line up the receivers replica C/A code with the received C/A code from the satellite.
The GP2021 is a 12 channel C/A code baseband correlator for use in NAVSTAR GPs satellite navigation receivers. The GP2021 complements the GP2015 and GP2010 C/A code RF downconverters.GP2021 is compatible with most 16 bit and 32 bit Microprocessors especially those from Motorola and Intel, with additional on-chip support for the ARM60 32 bit RISC processor. W
When using the ARM60 32 bit RISC microprocessor, the on-chip memory to support all of the GPS receiver functionality. 12 channels without the need for work, GP2021 allows 12 channels in any one does not work, in order to reduce power consumption and reduce the microprocessor load. During battery backup mode, GP2021 allows all of the function is not enabled, only the 32.768kHz oscillator and RTC (Real Time Clock, RTC) to maintain the work. GP2021 has 12 independent channels of the correlator, dual UART and RTC, power supply voltage of 5V, power consumption is less than 150mW, backup battery voltage is 2.2V. With 80L MQFP package, package size 14mm × 14mm × 2.0mm, suitable for GPS navigation receivers, GPS measuring receiver, GPS time transfer receiver applications. A typical GPS receiver circuit shown in the figure, the circuit from the GP2010 or GP2015 RF front-end, GP2021 correlator and ARM60 32 bit RISC microprocessor component. Because all of the satellites using the same frequency, ie Ll (1575.42MHz), so you can use an RF front-end. The sky coverage in order to achieve better results, it can use more than one antenna, so need to use their own RF front-end. In the RF section, GP2010 or GP2015 RF front-end for the digital baseband signals the completion of L1 down-conversion. The signals obtained in the GP2021 with internally generated satellite code-related. Each channel has its own separate code, you can simultaneously carry out 12 different satellite signal interception and tracking. The results related to the formation of the accumulated data to the microprocessor for processing, receive navigation information.