J4 ›› 2011, Vol. 38 ›› Issue (4): 143-147+180.doi: 10.3969/j.issn.1001-2400.2011.04.026

• Original Articles • Previous Articles     Next Articles

Cooperative communication scheme with 8PSK modulation constellations using LDPC codes

LI Lin;YUAN Chaowei;TIAN Xinji   

  1. (School of Info. and Comm. Eng., Beijing Univ. of Posts and Telecomm., Beijing  100876, China)
  • Received:2010-06-30 Online:2011-08-20 Published:2011-09-28
  • Contact: LI Lin E-mail:lipbupt@gmail.com

Abstract:

A new coded cooperation scheme with 8PSK modulation using LDPC codes is proposed for high spectral efficiency. Two users in the cooperative process transmit the data using 8PSK modulation over two frames. The transmitted information is stored if it is not decoded correctly by the cooperative partner over the first frame based on HARQ, and then the stored information and the next transmitted information are together decoded by the cooperative partner until the transmitted information over the first frame is decoded successfully, which improves the accuracy of decode due to adding parity information. Then the parity information of his cooperation partner is transmitted over the second frame for diversity. Analysis and simulation results show that the proposed method outperforms the no coded cooperation method and conventional coded cooperation method by benefit of 5dB and 3dB in the Raleigh block channel when the interuser channel has an SNR of 0dB and its BER is 10-3.

Key words: LDPC, coded cooperation, 8PSK modulation, HARQ, diversity