Abstract: Systems, methods and apparatus for an optimal achievable performance criterion for a wireless communication system. A method may include determining a joint average channel characteristic for each diversity branch of a plurality of diversity branches. The method may further include determining an optimal size of a first subset of the plurality of diversity branches based on the joint average channel characteristics. The method may further include determining an optimal choice for the first subset based on the joint average channel characteristics. The method may further include determining a number of pilot transmissions required based on the optimal choice of diversity branches for the first subset. The method may further include determining a second subset of the plurality of diversity branches based on instantaneous channel state information.