The Doppler Channel IP is a Doppler shift frequency (DSF) generator capable of introduce a shift frequency to samples as a phase offset. The IP was developed with the aim of allowing the performance evaluation of a low earth orbit (LEO) digital communication system. Unlike a software-based DSF generator, which might take several hours and even days for the stated purpose, a hardware-based DSF generator requires significantly less time. Run-time is reduced by several orders of magnitude.
Fixed Point Doppler Channel IP core
Overview
Key Features
- Support for orbital heights (h) in the range from 200 to 2000 km
- Support for carrier frequencies ( fc) in the range from 137 to 2200 MHz
- Support for sample frequencies ( fs) in the range from 500 Ksps to 500 Gsps
- Support variations in the initial elevation angle due to different latitudes, obstructions in the visibility region, and regulatory requirements
- Performance Figures
- Symbol rate of 0.62 Gsmpl/s at 620 MHz.
- Latency of 78.98 ns at 620 MHz.
Benefits
- Design-time configuration of the LEO altitudes range. Besides, the number of angles in the range from 0 to rad, followed by the pre-calculation of sine and cosine functions. The IP uses the fast inverse square root algorithm, set up with three iterations to ensure accuracy.
- Low-power and low-complexity design.
- AXI4-Stream interface for easy integration.
- Available for ASIC and FPGAs (AMD Xilinx, Intel).
Applications
- LEO Digital communication systems for which a Doppler channel is required
Deliverables
- VHDL source code or synthesized netlist with testbench
- HDL and Bit-accurate Matlab, C or C++ simulation models
- C++ firmware (Yocto/Petalinux compatible)
- Vivado IP Package
- Comprehensive documentation