Adaptive subcarrier and bit allocation in OFDMA systems supporting heterogeneous services

Orthogonal Frequency Division Multiple Access (OFDMA) is an efficient multiple access method for the future wireless systems. This paper studies the adaptive subcarrier and bit allocation problem in OFDMA systems to support heterogeneous services. The goal of the considered resource optimization technique is to maximize the total system throughput under the overall transmit power constraint while guaranteeing the QoS requirement of realtime users and supporting proportional fairness among non-realtime users. First, we introduce a Rate Adaptive (RA) resource allocation algorithm for non-realtime users and a Margin Adaptive (MA) algorithm for realtime users. Then, based on the previous algorithms, a novel algorithm is proposed to allocate the resource to both classes of users, which makes an efficient tradeoff between the resource usage of realtime users and non-realtime users. The algorithm is locally optimal solution provided that the MA and RA algorithms are utilized. Also, to reduce the computational complexity, a suboptimal method based on the balancing of the average power per subcarrier is also introduced. Monte Carlo simulation results show that all the proposed algorithms outperform the existing counterparts. The results also show that the suboptimal method for heterogeneous services can efficiently reduce the computational complexity at the cost of very little performance degradation.

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

[2]  Srikrishna Bhashyam,et al.  A sub-optimal joint subcarrier and power allocation algorithm for multiuser OFDM , 2005, IEEE Communications Letters.

[3]  Chi-Ying Tsui,et al.  A real-time sub-carrier allocation scheme for multiple access downlink OFDM transmission , 1999, Gateway to 21st Century Communications Village. VTC 1999-Fall. IEEE VTS 50th Vehicular Technology Conference (Cat. No.99CH36324).

[4]  Didem Kivanc-Tureli,et al.  Computationally efficient bandwidth allocation and power control for OFDMA , 2003, IEEE Trans. Wirel. Commun..

[5]  Songwu Lu,et al.  Fair queuing in wireless networks: issues and approaches , 1999, IEEE Wirel. Commun..

[6]  B.L. Evans,et al.  A low complexity algorithm for proportional resource allocation in OFDMA systems , 2004, IEEE Workshop onSignal Processing Systems, 2004. SIPS 2004..

[7]  Wei Wang,et al.  Resource allocation for heterogeneous services in multiuser OFDM systems , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[8]  John M. Cioffi,et al.  Increase in capacity of multiuser OFDM system using dynamic subchannel allocation , 2000, VTC2000-Spring. 2000 IEEE 51st Vehicular Technology Conference Proceedings (Cat. No.00CH37026).

[9]  Todor Cooklev,et al.  Air Interface for Fixed Broadband Wireless Access Systems , 2004 .

[10]  Jeffrey G. Andrews,et al.  Optimal power allocation in multiuser OFDM systems , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[11]  Yan Chen,et al.  A Novel Resource Allocation Algorithm for Real-time Services in Multiuser OFDM Systems , 2006, 2006 IEEE 63rd Vehicular Technology Conference.

[12]  Guodong Zhang,et al.  Subcarrier and bit allocation for real-time services in multiuser OFDM systems , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[13]  Beomsup Kim,et al.  On the use of linear programming for dynamic subchannel and bit allocation in multiuser OFDM , 2001, GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270).

[14]  Yan Chen,et al.  Subcarrier and bit allocation for OFDMA systems with proportional fairness , 2006, IEEE Wireless Communications and Networking Conference, 2006. WCNC 2006..