Results on vector biorthogonal partners

The concept of multiple input multiple output (MIMO) biorthogonal partners arises in many different contexts, one of them being multiwavelet theory. They also play a central role in the theory of MIMO channel equalization, especially with fractionally spaced equalizers. We explore some further theoretical properties of MIMO biorthogonal partners. These include the conditions for the existence of MIMO biorthogonal partners and their application in finding the solution for the least squares signal approximation problem.