Spectrally efficient cooperative coded schemes for next generation wireless networks

Both cooperative diversity and adaptive modulation provide significant enabling techniques for future generations of wireless communication networks. In this paper, we consider an IRCC (incremental redundancy cooperative coding) based cooperative network, which uses adaptive node transmission. Two cases are considered: (i) adaptive transmission only at relay nodes; (ii) adaptive transmission at source and relay nodes. The performance of these two cases are evaluated in terms of the average bit error rate (ABER) and the average spectral efficiency (ASE) and compared with those of noncooperative scheme without adaptive transmission over Rayleigh fading channels. Simulation results show that the IRCC scheme without adaptive modulation (AM) provides 28% more spectral efficiency compared with that of noncooperative case without AM. However, using AM and selecting the best relay in the IRCC scheme, this improvement increases to 100% at SNR of 1 dB.