<FONT face=Verdana>This paper considers antenna selection in the amplify-and-forward multiple-input multiple-output (MIMO) relay systems to maximize the capacity.Since the optimal antenna selection algorithm is of high complexity

a fast antenna selection algorithm is proposed.Through theoretical analysis and simulation

it is shown that if the source and destination have M and N antennas respectively

the relay only needs to use min(M

N) out of K antennas to achieve near optimal performance.The antenna selection criterion of the proposed algorithm is to maximize a lower bound of the capacity.This criterion reduces algorithmic complexity.This paper shows the derivation of the algorithm in detail

and analyze its complexity.Simulation results show that the proposed algorithm achieves comparable performance to the optimal algorithm

and has decreased complexity.