She Xiao-ming, Zhou Shi-dong, Yao Yan. Subband Adaptation Employing Turbo Coded Modulation for OFDM Transmissions[J]. Journal of Electronics & Information Technology, 2004, 26(8): 1312-1318.
Citation:
She Xiao-ming, Zhou Shi-dong, Yao Yan. Subband Adaptation Employing Turbo Coded Modulation for OFDM Transmissions[J]. Journal of Electronics & Information Technology, 2004, 26(8): 1312-1318.
She Xiao-ming, Zhou Shi-dong, Yao Yan. Subband Adaptation Employing Turbo Coded Modulation for OFDM Transmissions[J]. Journal of Electronics & Information Technology, 2004, 26(8): 1312-1318.
Citation:
She Xiao-ming, Zhou Shi-dong, Yao Yan. Subband Adaptation Employing Turbo Coded Modulation for OFDM Transmissions[J]. Journal of Electronics & Information Technology, 2004, 26(8): 1312-1318.
To improve the spectral efficiency for wireless data transmissions, a subband-by-subband adaptive turbo coded modulation scheme based on capacity evaluation is proposed for Orthogonal Frequency Division Multiplexing (OFDM). The target is to optimize the overall throughput under constant transmit power and target Bit-Error-Rate (BER). Sim-ulation results show that the adaptive OFDM scheme exhibits a 2.5~5 dB Signal to Noise Ratio (SNR) gain relative to fixed threshold adaptive turbo coded modulation when the transmitter knows the perfect channel information. However, the adaptation performance is degraded due to the feedback delay in time-varying channels. Then, the investigation indicates that decreasing the amounts of subbands, and utilizing the diversity characteristic adequately in frequency domain of OFDM is an effective approach to reduce the performance degradation.
Czylwik A.Adaptive OFDM for wideband radio channels.in Proc.IEEE Global Telecommunications Conf.(GLOBECOM96),London,U.K.,Nov.1996:713-718.[2]Lai S K,Cheng R S,Letaief K B,Murch R D.Adaptive trellis coded MQAM and power optimization for OFDM transmission.in IEEE Vehicular Technology Conference,Houston,USA,May 1999:290-295.[3]Keller T,Hanzo L.Adaptive modulation techniques for duplex OFDM transmission[J].IEEE Trans.on Vehicular Technology.2000,49(5):1893-1906[4]Leke A,Cioffi J M.Multicarrier systems with imperfect channel knowledge.Proc,PIMRC,Boston,USA,1998:549-553.[5]Soury M R,Pickholtz R L.Adaptive modulation with imperfect channel information in OFDM.in Proc.ICC,San Petersburg,Russia,2001:1861-1865.[6]Goff S L,Glavieux A,Berrou C.Turbo-codes and high spectral e～ciency modulation.in Proc.ICC,New Orleans,USA,1994:645-649.
DownLoad: