Overview
The COM-1827SOFT_GMSK_DEMOD is a continuous phase demodulator written in generic
VHDL.
The entire VHDL source code is deliverable. It is portable to a variety of FPGA targets
- Supports FSK, MSK, GFSK, GMSK modulations. These are constant amplitude modulation well suited for operation through power amplifiers near saturation.
- Flexible programmable features:
- Symbol rate up to fclk/4, where fclk is the processing clock frequency
- FSK, MSK, GFSK, GMSK
- Modulation index h. (0.5 for MSK and GMSK)
- Multiple BT products for Gaussian filters: 0.7, 0.5, 0.3, 0.25
- MSK, GMSK: coherent demodulation with excellent BER performance using trellis decoding (SOVA)
- FSK, GFSK: non-coherent demodulation with excellent BER performance using multi-symbol detection and trellis decoding (SOVA)
- 4-bit soft-decision demodulator output for best FEC decoder performance.
- Performance:
- BER < 10-5 at 9.2dB Eb/No
- ±50ppm symbol timing tracking
- Carrier frequency acquisition of 10% of symbol rate
- Acquisition threshold < 2dB Eb/No
- Provided with IP core:
- VHDL source code
- Matlab .m file for generating stimulus files for VHDL simulation of the demodulator and for end-to-end BER performance analysis at various signal to noise ratios
- VHDL testbench (stimulus file input, or back-to-back modem when used in conjunction with the CPM modulator IP core)
- BER tester
Documentation
Specifications
Complete VHDL/IP Core license agreement
Related products
CPM modulator IP core
SOQPSK modem IP core
PCM/FM demodulator IP core
Other demodulation IP cores
Ready-to-use digital CPM modem
Ready-to-use RF CPM modem