Modulation-Mode Assignment in SVD-Aided Downlink Multiuser MIMO-OFDM Systems

Multicarrier transmission such as OFDM (orthogonal frequency division multiplexing) is an established technique for radio transmission systems and it can be considered as a promising approach for next generation wireless systems. However, in order to comply with the demand on increasing available data rates in particular in wireless technologies, systems with multiple transmit and receive antennas, also called MIMO (multiple-input multiple-output) systems, have become indispensable for future generations of wireless systems. Due to the strongly increasing demand in high-data rate transmission systems, frequency non-selective MIMO links have reached a state of maturity and frequency selective MIMO links are in the focus of interest. In this field, the combination of MIMO transmission and OFDM can be considered as an essential part of fulfilling the requirements of future generations of wireless systems. However, single-user scenarios have reached a state of maturity. By contrast multiple users' scenarios require substantial further research, where in comparison to ZF (zero-forcing) multiuser transmission techniques, the individual user's channel characteristics are taken into consideration in this contribution. The performed joint optimization of the number of activated MIMO layers and the number of transmitted bits per subcarrier shows that not necessarily all user-specific MIMO layers per subcarrier have to be activated in order to minimize the overall BER under the constraint of a given fixed data throughput.

[1]  Lie-Liang Yang,et al.  SVD Assisted Joint Transmitter and Receiver Design for the Downlink of MIMO Systems , 2008, 2008 IEEE 68th Vehicular Technology Conference.

[2]  Kwang Bok Lee,et al.  Transmit power allocation for BER performance improvement in multicarrier systems , 2004, IEEE Transactions on Communications.

[3]  M. Dohler,et al.  MIMO systems with adaptive modulation , 2004, IEEE Transactions on Vehicular Technology.

[4]  Matthias Patzold,et al.  Mobile Fading Channels , 2003 .

[5]  Heung Ki Baik,et al.  Adaptive OFDM with channel predictor over frequency-selective and rapid fading channel , 2003, 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003..

[6]  Burton R. Saltzberg,et al.  Multi-Carrier Digital Communications: Theory and Applications of Ofdm , 1999 .

[7]  Andreas Ahrens,et al.  Modulation-Mode and Power Assignment in SVD-Equalized MIMO Systems , 2008 .

[8]  Khaled Ben Letaief,et al.  Multiuser OFDM with adaptive subcarrier, bit, and power allocation , 1999, IEEE J. Sel. Areas Commun..

[9]  John M. Cioffi,et al.  Spatio-temporal coding for wireless communication , 1998, IEEE Trans. Commun..

[10]  Kwang Bok Lee,et al.  Transmit power adaptation for multiuser OFDM systems , 2003, IEEE J. Sel. Areas Commun..

[11]  Ramjee Prasad,et al.  OFDM for Wireless Multimedia Communications , 1999 .

[12]  Lizhong Zheng,et al.  Diversity and multiplexing: a fundamental tradeoff in multiple-antenna channels , 2003, IEEE Trans. Inf. Theory.

[13]  J.E. Mazo,et al.  Digital communications , 1985, Proceedings of the IEEE.

[14]  Douglas L. Jones,et al.  Computationally efficient optimal power allocation algorithms for multicarrier communication systems , 2000, IEEE Trans. Commun..

[15]  V. Kühn.  Wireless Communications over MIMO Channels: Applications to CDMA and Multiple Antenna Systems , 2006 .

[16]  Gregory G. Raleigh,et al.  Multivariate modulation and coding for wireless communication , 1999, IEEE J. Sel. Areas Commun..