2002 Suzuki Esteem Loud noise on highway coming from transm

The car is a 2002 SUZUKI ESTEEM GL 1.8, sedan, automatic transmission.

On the highway, above 55-60 mph, there is a noise which increases if I accelerate more. The noise comes from near to my feet. The noise is periodical, "rotational", and not much smothered, . It is almost the same type of noise you hear when you shake a pencil in a glass (but low register). Or the noise that a shaky exhaust pipe would do. But I already got it checked. I also check all the fluid levels.

The noise also happens when the car goes on road irregularities at high speed.

After having being on the highway, the noise continues for a few minutes, at low speed, only when I turn.

I had a look under the car, and the elements that are close to my feet are:
- the automatic transmission
- the connecting rod from it to the wheel
- the shock absorber
- the steering link
- the connections between the car frame and the wheel
- the wheel.

I was first thinking that the problem is coming from the automatic transmission but I reached 60 mph with the 3rd and the 4th gear, it makes no difference. Also, the casing is pretty thick and filled with oil so I don't think the noise would be the same. Maybe the torque converter?

My last conclusions are that the noise comes from the shaft drive between the transmission and the connecting rod that goes to the wheel. The change in angle when the wheel goes on an irregularity could explain why it happens in this situation too.