Sine PWM for Three level T-Type Neutral Point Clamped Inverter

Hi I would like to implement Sine PWM(SPWM) for T-type Three level MultiLevel Inverter(MLI); I reviewed journals for SPWM implementation of T-type three level MLI, based on that , this is my understanding,

1) generating three phase references,

2) from each references generate one set of complementary pulses,

3) In T-type, we have vertical and horizantal leg for each phase, (vertical leg has series connected switches (Q1,Q4), horizantal leg has back to back connected (Q2,Q3).

4) for positive half cycle of reference, Q1 & Q2 operate in complementary with switching freq ,Q3 & Q4- completely off for positive half cycle,

5) for negative half cycle of reference, Q3 & Q4 operate in complementary with switching freq, Q1 & Q2 - completely off for negative half cycle

whether this understanding is correct?

Does anyone have idea on the same, also refer related journals if any...