FMCW Radar using FSK Superimposed LFM ramp
First thing first: Once you start talking about stepped FM waveforms with the goal of achieving LFM-like range resolutions you are introducing a more complex receiver along with other associated disadvantages. Stepped-LFM waveforms require that you process each pulse individually, and thus the receiver must reconfigure itself for every pulse which are at different frequencies. Having said that, you must transmit multiple pulses (think multiple PRIs) in order to reap the range resolution benefits. Contrast this to an LFM system that has the large enough instantaneous bandwidth where it can achieve high range resolution with only a single pulse.
This documentation implies that you use the stepped-FM portions of the waveform to achieve high range resolution and the FSK processing to perform Doppler filtering.
Specifically, with this waveform you can process the strictly stepped-FM portions (the solid black lines) as mentioned before to achieve the range resolution required. You can then pass the FSK portions (dotted lines) through a Doppler filter bank, after appropriate mixing and integration, to yield the target velocity.
As you can see, the receiver for such a system sounds pretty complex! In the past, hardware was not up to par to provide the instantaneous bandwidth and computational power that we have today, so great effort was made to design these complex receivers to achieve the desired performance.
Thankfully, hardware has come a long way even since this datasheet was published and we now have access to high instantaneous bandwidth systems which allow for simpler receiver designs. Modern DAC/ADC and embedded processor technology has enabled multi-GHz bandwith waveform generation  and processing. We can easily generate a multi-hundred-MHz LFM pulse and process it digitally via a matched filter using a rather simple receiver design.