Enhancement the Performance of MANET (Mobile Ad-hoc Network) using spatial diversity. Spatial diversity implemented using cooperative transmission technique in Medium access control (MAC) layer level protocol. In noisy environment limit the network performance like coverage area, limit number of node, degrade packet transmission rate, increase packet loss rate etc. In this paper enhance the source to destination transmission range, minimize the packet loss, improve packet transmission rate and appropriate end to end delay. When direct link is fail to transmit packet then Cooperative scheme help to transmit packet. Cooperative scheme is to help the packet transmission with five handshakes instead of four. This scheme implemented in MANET network on MAC layer protocol. Cooperative scheme improve the performance with help of intermediate node between sources to destination. We are performance analysis using discrete simulator NS-2 in MANET. Our performance based on MAC layer level with cooperative scheme in IEEE WLAN standard CSMA/CA protocol.