From Channel Impulse Response (CIR) to Power Delay Profile (PDP)

I have a generator that generates channel impulse response (CIR) between two points (tx and rx) in a 3D closed space (a room).

From CIR, I get power delay profile by squaring its absolute value.

Here are some questions that I am having difficulty to understand:

Let h be the CIR.

(1) I found in a textbook: PDP = (abs(h).^2)./dt; where dt is 1/fs, fs being sampling frequency.

Why do we need to multiply with dt?

(2) To compare two PDPs, it seems that I need to normalize both of the PDPs. Correct? Now, since PDP comes out of CIR, do I normalize CIR as well as PDP or only one of them (which one?)?

I hope someone can answer them.

Thank you for reading and taking time to reply.

Cheers, G