In　this　paper,　we　have　proposed　link　balancing　scheme　based　on　MIMO　switching　for　the　high　speed　wireless　access　system　via　dual-hop　MIMO　relays,　and　analyzed　the　capacity　of　different　MIMO　transmission　mode.　From　these　studies,　we　can　conclude　that　the　relayed　MIMO　system　can　support　high　speed　group　mobility　and　the　link　balancing　method　is　able　to　enhance　the　transmission　performance.