sentences:  Before the introduction of Cooperative-MIMO, joint processing among cellular base stations was proposed to mitigate inter-cell interference, and Cooperative diversity offered increased diversity gain using relays, but at the cost of poorer spectral efficiency.However, neither of these techniques exploits interference for spatial multiplexing gains, which can dramatically increase spectral efficiency.In 2001, Cooperative MIMO was introduced by Steve Shattil, a scientist at Idris Communications, in a provisional patent application, which disclosed Coordinated Multipoint and Fixed Relays, followed by a paper in which S. Shamai and B.M.