In present scenario, there is a need of improving our future wireless communication system, since system suffers from the problem of low spectral efficiency, low link reliability, medium data rates and the problem of frequency selective fading. This problem can be solved by using OFDM signals. The advantage of OFDM is that it has the capacity of overcoming the frequency selective fading problem, high spectral efficiency, and low computational complexity. Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and to increase the system capacity on time-variant and frequency-selective channels, resulting in a multiple-input multiple-output (MIMO) configuration. In these proposed paper system transmit a single signal using transmit diversity (TD) after that relay selection(RS) is done using Decode-and-forward (DF) protocol and Amplify-and–forward protocol(AF)and signal is transferred towards the receiver.

1. D. H. Johnson and D. E. Dudgeon, 1993 "Array Signal Processing:Conceptsand Techniques," Englewood Cliffs, NJ: Prentice-Hall.
2. G. J. Foschini, 1996. "Layered space-time architecture for wireless communication in a fading environment when using multiple antennas," Bell Labs. Tech. J. , vol. 1, no. 2, pp. 41–59, Autumn .
3. P. A. Zulch, J. S. Goldstein, J. R. Guerci, and I. S. Reed Nov. 1998,"Comparison of reduced-rank signal processing techniques,"in Proc. 32nd Asilomar Conf. Signals, Syst. Comput. , PacificGrove, CA.
4. L. Tong and S. Perreau, Oct. 1998 "Multichannel blind channel estimation: From subspace to maximum likelihood methods,"Proc. IEEE, vol. 86, pp. 1951–1968.
5. . S. Thoen, L. Van der Perre, B. Gyselinckx, and M. Engels, Jan2001 "Performance analysis of combined transmit-SC/receive-RC," IEEE Trans. Commun. , vol. 49, no. 1, pp. 5 – 8,.
6. M. L. Honig and J. S. Goldstein, Jun 2002 "Adaptive reduced-rank interference suppression based on the multistage Wiener filter,"IEEE Trans. Commun. , vol. 50, no. 6, pp. 986–994,. .
7. Berenguer, X. Wang, and V. Krishnamurhty, Nov. 2005 "Adaptive MIMO antenna selection via discrete stochastic optimization," IEEE Trans. Signal Process. , vol. 53, no. 11, pp. 4315–4329,
8. Fan and J. Thompson, May 2007. "MIMO configurations for relay channels: Theory and practice," IEEE Trans. wirelessCommun. , vol. 6, no. 5, pp. 1774–1786.
9. R. C. de Lamare, R. Sampaio-Neto, and A. Hjrungnes, Dec. 2007 "Jointiterative interference cancellation and parameter estimationfor CDMA systems," IEEE Commun. Lett. , vol. 11, no. 12, pp. 916–918.
10. S. W. Peters and R. Heath, 2008 "Non regenerative MIMO relaying with optimal transmit antenna selection," IEEE Signal Process. Lett. , vol. 15, pp. 421–424.
11. H. Zhang, H. Dai, and B. L. Hughes, Jan. 2009. "Analysis on the diversitymultiplexing tradeoff for ordered MIMO SIC receivers," IEEE Trans. Commun. , vol. 57, no. 1, pp. 125–133,
12. R. Fa and R. C. de Lamare, May 2011 "Multi-branch successive interference cancellation for MIMO spatial multiplexing systems: Design, analysis and adaptive implementation," IET Commun. , vol. 5, no. 4, pp. 484–494.
13. Transmit Diversity and relasy Selection algorithm for Multirelay Cooperative MIMO systems ,"IEEE,Rodrigo C. de Lamare,Senioor Member ,IEEE.
14. Batu Chalise, Yimin Zhang, and Moeness Amin, , MAY 2012Ied "Local CS with Direct Link," IEEE COMMUNICATIONS LETTERS, pp. 622-625 VOL. 16, NO. 5. , Based Selection Beam forming for AF MIMO Relay System.

Af df Mimo ofdm Relay Selection(rs) Transmit Diversity (td).