BER-Based Chunk Allocation in Multiuser OFDM Wireless Systems

This paper analyzes throughput performance of the chunk-based subcarrier allocation by considering the average bit-error-rate (BER) constraint over a chunk in downlink multiuser orthogonal frequency division multiplexing (OFDM) transmission. The outage probabilities per subcarrier are compared between the average BER-constraint based chunk allocation and the average signal-to-noise-ratio (SNR) based chunk allocation. The effects of system parameters, including the coherence bandwidth, the number of subcarriers per chunk, and the number of users, are evaluated. The numerical results show that, when the chunk bandwidth is smaller than the coherence bandwidth, the average downlink throughput of the chunk-based subcarrier allocation is very close to that of the single-subcarrier-based allocation. The effective throughput of the average BER-constraint based chunk allocation is higher than that of the average SNR based chunk allocation, especially when the number of users is large.

[1]  Hui Liu,et al.  Effect of traffic channel configuration on the orthogonal frequency division multiple access downlink performance , 2005 .

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

[3]  Laurence B. Milstein,et al.  Multicarrier CDMA overlay for ultra-wideband communications , 2004, IEEE Transactions on Communications.

[4]  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).

[5]  Andrea J. Goldsmith,et al.  Degrees of freedom in adaptive modulation: a unified view , 2001, IEEE Trans. Commun..

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

[7]  Mamoru Sawahashi,et al.  MCI cancellation for multicode wideband CDMA systems , 2002, IEEE J. Sel. Areas Commun..

[8]  Jun Chen,et al.  Performance of wideband CDMA systems with complex spreading and imperfect channel estimation , 2001, IEEE J. Sel. Areas Commun..

[9]  Yiqing Zhou,et al.  Downlink transmission of broadband OFCDM systems-part IV: soft decision , 2006, IEEE Journal on Selected Areas in Communications.

[10]  Laurence B. Milstein,et al.  Adaptive LMS Filters for Cellular CDMA Overlay Situations , 1996, IEEE J. Sel. Areas Commun..

[11]  Mamoru Sawahashi,et al.  Downlink transmission of broadband OFCDM Systems-part I: hybrid detection , 2005, IEEE Transactions on Communications.

[12]  Laurence B. Milstein,et al.  CDMA overlay situations for microcellular mobile communications , 1995, IEEE Trans. Commun..