Capacity analysis of simple and opportunistic feedback schemes in OFDMA Systems

We mathematically analyze the system capacity of one simple feedback scheme and two opportunistic feedback schemes: simple-feedback, max-feedback, and max-n-feedback schemes, in orthogonal frequency division multiple access (OFDMA) systems. The maximum signal-to-noise ratio (SNR) scheduling strategy can be used as a scheduling criterion at base stations (BSs). In the simple-feedback scheme, each user sends the received SNRs of all sub-bands to the BS for frequency domain scheduling (FDS) at the BS. In two opportunistic feedback (OFB) schemes: max-feedback and max-n-feedback schemes, each user sends the reduced number of SNR values among the SNR values of all sub-bands in order to reduce the feedback overhead. In this paper, we derive the system capacity of the simple-feedback and max-feedback schemes in a closed-form. In addition, we derive the upper-bound of the system capacity of the max-n-feedback scheme. The analytical results agree with computer simulation results. Furthermore, the results show that the OFB schemes can reduce the feedback overhead, while the multiuser diversity can be maintained as the number of user increases.

[1]  Robert W. Heath,et al.  Opportunistic feedback for downlink multiuser diversity , 2005, IEEE Communications Letters.

[2]  Mathias Johansson,et al.  Benefits of multiuser diversity with limited feedback , 2003, 2003 4th IEEE Workshop on Signal Processing Advances in Wireless Communications - SPAWC 2003 (IEEE Cat. No.03EX689).

[3]  Young-June Choi,et al.  QoS-aware Selective Feedback and Optimal Channel Allocation in Multiple Shared Channel Environments , 2006, IEEE Transactions on Wireless Communications.

[4]  I. M. Pyshik,et al.  Table of integrals, series, and products , 1965 .

[5]  Hyung-Myung Kim,et al.  Opportunistic Feedback Assisted Scheduling and Resource Allocation in OFDMA Systems , 2006, 2006 10th IEEE Singapore International Conference on Communication Systems.

[6]  Raymond Knopp,et al.  Information capacity and power control in single-cell multiuser communications , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[7]  Khaled Fazel,et al.  Multi-Carrier and Spread Spectrum Systems , 2003 .

[8]  S. Wang,et al.  IEEE standard 802.16: a technical overview of the WirelessMAN/sup TM/ air interface for broadband wireless access , 2002, IEEE Communications Magazine.

[9]  Mohamed-Slim Alouini,et al.  How much feedback is multi-user diversity really worth? , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[10]  Mohamed-Slim Alouini,et al.  Further results on selective multiuser diversity , 2004, MSWiM '04.

[11]  H. N. Nagaraja,et al.  Order Statistics, Third Edition , 2005, Wiley Series in Probability and Statistics.

[12]  L.J. Cimini,et al.  A simplified opportunistic feedback and scheduling scheme for OFDM , 2004, 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring (IEEE Cat. No.04CH37514).

[13]  V. Roman,et al.  Broadband wireless access solutions based on OFDM access in IEEE 802.16 , 2002 .

[14]  I. S. Gradshteyn,et al.  Table of Integrals, Series, and Products , 1976 .

[15]  David Tse,et al.  Opportunistic beamforming using dumb antennas , 2002, IEEE Trans. Inf. Theory.

[16]  Young-June Choi,et al.  Selective channel feedback mechanisms for wireless multichannel scheduling , 2006, 2006 International Symposium on a World of Wireless, Mobile and Multimedia Networks(WoWMoM'06).

[17]  K. Fazel,et al.  Multi-Carrier and Spread Spectrum Systems: Fazel/Spread Spectrum , 2004 .