Acta Metallurgica Sinica(English letters) ›› 2013, Vol. 20 ›› Issue (6): 18-23.doi: 10.1016/S1005-8885(13)60103-X

• Wireless • Previous Articles     Next Articles

Estimation of synchronization impairments in multi-relay DF cooperative networks

  

  1. Key Lab of Universal Wireless Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China
  • Received:2013-05-20 Revised:2013-08-29 Online:2013-12-31 Published:2013-12-27
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (61171105).

Abstract:

Cooperative communication systems can effectively increase channel capacity and combat fading. Effective cooperation requires synchronization impairments such as multiple timing offsets and multiple carrier frequency offsets to be accurately estimated and mitigated. This paper seeks to address the joint estimation of synchronization impairments in multi-relay decode-and-forward (DF) cooperative networks. Firstly, a simple yet effective estimation method based on the devised training signals is presented for achieving synchronization. Then, an iterative algorithm is further derived in order to improve the performance associated with the estimation of synchronization impairments. Our proposed algorithm converts the difficult multiple parameter estimation problem into more tractable sub-problems of estimating many individual impairments pairs for the independent relays. Simulations indicate that, the proposed estimator can asymptotically achieve the mean square error (MSE) for the perfectly timing or frequency synchronized case.

Key words:

cooperative communication, decode-and-forward, synchronization