How do I show that someone is speaking the quotation I have in my essay?

For example, I have this quotation.. "I was getting quite cold. I couldn't do anything about it but it was driving me crazy! I had to do something about it." (Smith 11) Bobby being the narrator, by the way.. So, how would I show that Bobby was saying that? Would I do this?

[Bobby] "I was getting quite cold..." (Smith 11)

Please help in telling me if what I have just above here is correct, or maybe do I put his name in square brackets within the quotation marks at the beginning, at the end, or outside of the quotation marks at the end. Your help is appreciated!

you could put:
Bobby said: "I was getting quite cold. I couldn't..." (Smith 11) or a variation of this
OR
"I was getting quite cold..." (Smith 11) --Bobby (Not sure if this is gramatically correct, so check it out)

I'd have to see it in the larger context. Generally, you will introduce a quote or clarify it in some manner instead of using the quote as a sentence on its own; it would be appropriate to mention the speaker at that time. Something like: Bobby's frustration with his situation becomes evident when he says, "I was getting quite cold. I couldn't do anything about it but it was driving me crazy! I had to do something about it" (Smith 11).

Put the period on the outside of the parenthetical citation (it is awkward, I know!).

The brackets are used when you change or omit something from the original text or if you want to show that an error was in the original and not your error (in that case, you include the error and then [sic]).

yes, that thing about putting the period outside the quotation marks is important. Did you catch what Noto meant about that?

If you are talking about a character in a story, you can write this:
Bobby says, "I was getting quite cold. I couldn't do anything about it but it was driving me crazy! I had to do something about it" (Smith 11).

or
The narrator (Bobby) explains, "I was....

:-)