This IP is a part of LabVIEW FPGA RF Communications Library available on NI Labs.

This IP performs digital demodulation of a QPSK modulated signal. The specs of this IP are as follows:

1. Corrects frequency offsets upto 50kHz.

2. Corrects symbol timing offsets upto 0.5% of the symbol rate.

3. Implements a 31 tap matched filter with programmable filter roll-off (alpha) in the range (0.4, 1.0).

4. Has the ability to demodulate in the presence of doppler shift upto 75kHz at doppler rate <=2kHz/s.

5. Maximum clock rate= 20MHz.

6. IP requires two samples per symbol (Maximum Symbol rate = 10MS/s).

7. Device utilization summary ( Xilinx Virtex II Pro P30)

Number of BUFGMUXs 7 out of 16 43%

Number of External IOBs 403 out of 556 72%

Number of MULT18X18s 71 out of 136 52%

Number of RAMB16s 18 out of 136 13%

Number of SLICEs 6498 out of 13696 47%

Required: Fixed-Point Math Library for LabVIEW FPGA

Please post your comments, feedback, queries so that we can improve the demodulator design.