Discourse analysis is one form of structuralism - it observes patterns of discourse.
Meaning comes from the deep structure of the language, that which is found beyond the normal semantic and grammatical categories. Structualism is hard to define, it implies more of a statement regarding a perspective of reality than an organized method or system. It was a reaction to the traditional apporach to analyzing texts. So, structualism seeks to understand meaning by observing the deeper levels of thought expressed by language. The whole of a statement is explained by examining the relationships of its parts.