This paper proposes a cooperative wireless relay network consisting of a one-source-one-destination node pair and N relay nodes in three wireless communication environments, i.e., jamming, node geometry, and channel uncertainty. The main objective of this paper is to analytically derive the optimal cooperative amplify-and-forward (AF) wireless relay matrix under three conditions with the relay power constraint based on the minimum mean square error (MMSE) criterion. Using the derived amplifying relay matrix, the MMSE cost function and achievable rate will be investigated numerically and analytically.