LMX2571: LMX2571

GMSK and G2B modulation

I want to build AIS (AIS Automatic Identification System) and DSC (Digital Selective Calling Rec. ITU-R M.493-14) transceiver using the LMX2571 chip.

AIS Automatic Identification System

• Channel A 161.975 MHz (87B);

• Channel B 162.025 MHz (88B);

• AIS messages are transmitted using GMSK modulation. The GMSK modulator BT-product used for transmission of data should be 0.4 maximum (highest nominal value);

• The GMSK coded data should frequency modulate the VHF transmitter. The modulation index should be 0.5;

• The transmission bit rate is 9600bit/s.

Digital Selective Calling

• Channel 70 156.525 MHz;

• Frequency modulation with a pre-emphasis of 6 dB/octave (phase modulation) with frequency-shift of the modulating sub-carrier for use on VHF channels:

– frequency-shift between 1 300 and 2 100 Hz; the sub-carrier being at 1 700 Hz;

– the frequency tolerance of the 1 300 and 2 100 Hz tones is ±10 Hz;

– the modulation rate is 1 200 (bit/s) * (1 ± 30 * 10−6);

– the index of modulation is 2.0 ±10%.

Issues:

1. Tell me please, is it possible to use the LMX2571 chip to create the above types of GMSK and G2B modulations?

    

2. If this can be done with the help of LMX2571, you could not help in compiling a table of LUT values for GMSK and G2B?

    

3. What can I read more than SNAA309?

    

Thank you!