Adaptive Modulation Based Relay Selection and Power Allocation in Cooperative OFDM Wireless Networks

  • Nianlong Jia
  • Wenjiang Feng
  • Najashi Bara’u Gafai
  • Weiheng Jiang
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 246)


Several problems that hinder the optimal performance of multiple relays cooperative OFDM wireless networks have been identified recently. Power allocation and relay selection are some of the problems encountered in these systems. In this paper, a bit reloading (BR) OFDM relaying scheme which solves the problem of both power allocation and relay selection in multiple relays cooperative OFDM wireless networks by selecting the best relay to retransmit the OFDM signal is presented. This method varies from other methods in open literature because bit loading is executed at each hop i.e. from source to relay, and from relay to the destination. Because the bottleneck of bit loading with regard to source-to-relay-to-destination subchannel is eliminated, our proposed scheme achieves more power gain and end-to-end data rate. The theoretic analysis and simulation result also demonstrates our scheme has a better performance.


Cooperative communications OFDM Relay selection Bit loading 


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Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Nianlong Jia
    • 1
  • Wenjiang Feng
    • 1
  • Najashi Bara’u Gafai
    • 1
  • Weiheng Jiang
    • 1
  1. 1.College of Communication EngineeringChongqing UniversityChongqingChina

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