Joint physical layer coding and network coding for bidirectional relaying


Journal Article

We consider a communication system where two transmitters wish to exchange information through a central relay. The transmitter and relay nodes exchange data over synchronized, average power constrained additive white Gaussian noise channels with a real input with signal-to-noise ratio (SNR) of ssr. An upper bound on the capacity is 1/2 log (1+ ssr) bits per transmitter per use of the multiple access phase and broadcast phase of the bidirectional relay channel. We show that, using lattice codes and lattice decoding, we can obtain a rate of 1/2 log (1/2 + ssr) bits per transmitter, which is essentially optimal at high SNR. The main idea is to decode the sum of the codewords modulo a lattice at the relay followed by a broadcast phase which performs SlepianWolf coding. We also show that if the two transmitters use identical lattices with minimum angle decoding, we can achieve the same rate of 1/2 log(1/2 + snr). The proposed scheme can be thought of as a joint physical-layer network-layer code which outperforms other recently proposed analog network coding schemes. © 2006 IEEE.

Full Text

Duke Authors

Cited Authors

  • Wilson, MP; Narayanan, K; Pfister, HD; Sprintson, A

Published Date

  • November 1, 2010

Published In

Volume / Issue

  • 56 / 11

Start / End Page

  • 5641 - 5654

International Standard Serial Number (ISSN)

  • 0018-9448

Digital Object Identifier (DOI)

  • 10.1109/TIT.2010.2068750

Citation Source

  • Scopus