GPS Signal Tap-L2C is an L2 frequency GPS Receiver front end which serves as a programmable real time source of digitized GPS signal for a variety of desktop research and development related to signal processing. The Signal Tap consists of a three stage RF down converter whose third IF can be sampled and stored for analysis by the user at a programmable frequency. The Signal Tap-L2C allows the user to acquire samples for predefined intervals of time or continuously in real time. The GPS Signal Tap-L2C has two main blocks: the RF Down converter and the Signal Buffer. The RF down converter gets the input GPS satellite L2C signal from an antenna-cable assembly. It uses mixers, local oscillators and band pass filters to down convert the carrier to a low IF. The IF is then sampled by a chosen sampling frequency to generate digitized IF signal of the satellites. The Signal Buffer collects the digitized GPS L2C signal samples and temporarily stores them in the on-board RAM before sending them to the host computer through the USB interface. A powerful 32 bit floating DSP with 400 MFLOPS forms the heart of the signal buffer which has the capacity to store 64 Mbits of sampled data before downloading into the PC. The user can configure the GPS Signal Tap-L2C from the PC based software and start/stop acquisition for either predefined time interval or continuously, at the pre configured sampling rate. The data acquired by the software is stored in the PC hard disk and can be used with the software developed by the user or with popular mathematical programs such as MATLAB.
- GPS L2 frequency RF Front End
- Sends GPS L2C signal to the PC platform enabling research and development of algorithms for L2C signal acquisition, tracking and testing the performance in indoor, E911 or other demanding applications
- Wide range of user programmable sampling clock frequencies between 2 MHz and 7*MHz in steps of 1KHz
- Options for "snap shot" (predefined interval) and uninterrupted real time data acquisition
- 2 MHz IF bandwidth
- Ideally suited for research in high sensitivity correlator
- Choice of 1 or 2 bit digitized outputs
- Uninterrupted real time sample data collection
- Option for “Snap shot” (predefined interval) and uninterrupted real data acquisition
- Snap shot data acquisition with duration configurable upto 130 seconds
USB 2.0 interface to host computer, which supports both full speed transfer at 12MBPS and high speed transfer at 480MBPS.
- PC Based user interface software to communicate with the target
- Firmware upgrade possible through USB port
- Designed to work with an active antenna
- Signal Analysis software to validate the collected data
- Future growth option to download Signal Processing Algorithms
- Sample MATLABTM programs for L2C signal acquisition
The GPS Signal Tap-L2C can be used for a variety of purposes by engineers, scientists and researchers involved in the processing and analysis of the GPS Signal. Not only can it be used to realize or experiment with individual functional building blocks of GPS receiver but also to build a complete software intensive Receiver integrated with the engineer's chosen software development environment.
New algorithms under development can be tested with real time GPS L2C signal acquired from the Signal Tap-L2C. Receiver designers working on new architectures for emerging applications such as the E911 can try out their ideas on their desktop PC equipped with the Signal Tap-L2C.
With its 2 MHz IF bandwidth and a provision for higher sampling frequencies, the Signal Tap-L2C is ideally suited for research on the impact of sampling frequency on the acquisition and tracking performance and resource usage in a Software GPS receiver in real time kinematics.
The L2C Signal Tap can be used with active GPS L2 frequency capable antenna, antenna re-radiation system or with single or multi-channel GPS L2C simulators.
The GPS signal Tap can be accessed in real time from user's own software development environment, by using the system call provided along with the .DLL.
Frequency
GPS L2 at 1227.6 MHz
GPS Code
CM and CL
Sampling Rate
2 Mz to 7* MHz (configurable at step size of 1KHz)
Max.Sampling rate for continous data transfer
4.7 MHz, 1 bit sampling with Full speed host interface, 7MHz , 2-bit sampling with high speed host interface.
IF Bandwidth
2 MHz
Signal Gain at the output of second IF Stage
120dB
Snap Shot Interval
Configurable upto 130 seconds
Physical Characteristics
Dimensions
6" X 4" X 2"
Weight
300 grams
lectrical Characteristics
Power consumption
1A (Typical)
Input Power
6V DC
Computer
IBM compatible PC
Operating System
Windows 98/2000/XP
RAM
Processor speed of 1GHz,256 MB or above for offline processing and 2.4GHz 512 MB or above for Real time.
The Basic GPS Signal Tap-L2C Includes: |
