Proportional fair-based joint subcarrier and power allocation in relay-enhanced orthogonal frequency division multiplexing systems

There has emerged lots of interests in the resource allocation of the relay-enhanced orthogonal frequency division multiplexing (OFDM) system. Most of the existing research works are with the aim to maximise the transmit rate of the system. However, few of them have taken into account the fairness requirements. In order to achieve the trade-off between the system transmit rate and user fairness, this study originally studies the optimality of proportional fairness (PF) in a downlink relay-enhanced OFDM system, where one source communicates with multiple destinations by the aid of one or many relays. We investigate the joint subcarrier and power allocation problem with PF constraint. Firstly, the resource allocation problem is formulated. Then, the problem is studied in the framework of concave maximisation. By using mathematical decomposition techniques, the optimisation problem is decomposed into multiple-layer subproblems which can be resolved efficiently. With this method, a cross-layer algorithm is derived to achieve the near optimal solution. Finally, numerical results are illustrated. Compared to the existing schemes, our proposed algorithm can both maximise the sum of logarithmic per user average transmit rate and enhance the system transmit rate.

[1]  Wei Yu,et al.  Constant-power waterfilling: performance bound and low-complexity implementation , 2006, IEEE Transactions on Communications.

[2]  Zhang Zhang,et al.  Adaptive optimal transmit power allocation for two-hop non-regenerative wireless relaying system , 2004, 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring (IEEE Cat. No.04CH37514).

[3]  Shuyuan Yang,et al.  Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System , 2008, EURASIP J. Adv. Signal Process..

[4]  W. Mohr,et al.  Data rate estimates, range calculations and spectrum demand for new elements of systems beyond IMT-2000 , 2002, The 5th International Symposium on Wireless Personal Multimedia Communications.

[5]  Hui Liu,et al.  Resource Allocation for OFDMA Relay Networks With Fairness Constraints , 2006, IEEE Journal on Selected Areas in Communications.

[6]  Koushik Kar,et al.  Cross-layer rate optimization for proportional fairness in multihop wireless networks with random access , 2006, IEEE Journal on Selected Areas in Communications.

[7]  E. Calvo,et al.  Resource allocation in multihop OFDMA broadcast networks , 2007, 2007 IEEE 8th Workshop on Signal Processing Advances in Wireless Communications.

[8]  Markus Herdin.  A Chunk Based OFDM Amplify-and-Forward Relaying Scheme for 4G Mobile Radio Systems , 2006, 2006 IEEE International Conference on Communications.

[9]  Armin Wittneben,et al.  On the Optimal Power Allocation for Nonregenerative OFDM Relay Links , 2006, 2006 IEEE International Conference on Communications.

[10]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[11]  Dong-Ho Cho,et al.  Fairness-Aware Adaptive Resource Allocation Scheme in Multihop OFDMA Systems , 2007, IEEE Communications Letters.

[12]  Petar Popovski,et al.  Proportional fairness in multi-carrier system: upper bound and approximation algorithms , 2006, IEEE Communications Letters.

[13]  Basak Can,et al.  Implementation Issues for OFDM-Based Multihop Cellular Networks , 2007, IEEE Communications Magazine.

[14]  Daniel Pérez Palomar,et al.  A tutorial on decomposition methods for network utility maximization , 2006, IEEE Journal on Selected Areas in Communications.

[15]  Ye Li,et al.  Orthogonal Frequency Division Multiplexing for Wireless Communications (Signals and Communication Technology) , 2006 .

[16]  Pablo Soldati,et al.  Mathematical decomposition techniques for distributed cross-layer optimization of data networks , 2006, IEEE Journal on Selected Areas in Communications.

[17]  Luc Vandendorpe,et al.  Power Allocation for OFDM Transmission with DF Relaying , 2008, 2008 IEEE International Conference on Communications.

[18]  Mazen O. Hasna,et al.  Harmonic mean and end-to-end performance of transmission systems with relays , 2004, IEEE Transactions on Communications.

[19]  Armin Wittneben,et al.  Power Allocation Schemes for Amplify-and-Forward MIMO-OFDM Relay Links , 2007, IEEE Transactions on Wireless Communications.

[20]  Hoon Kim,et al.  A proportional fair scheduling for multicarrier transmission systems , 2004 .