The Optimal Subchannel and Bit Allocation Problem for OFDM
The advantages of the orthogonal frequency division multiplexing (OFDM) are high spectral efficiency, resiliency to RF interference, and lower multi-path distortion. To further utilize vast channel capacity of the multiuser OFDM, one has to find the efficient adaptive subchannel and bit allocation among users. In this paper, we propose an 0-1 integer programming model formulating the optimal subchannel and bit allocation problem of the multiuser OFDM. We provide an efficient Lagrangian dual formulation with fast solution approach. Simulation results are provided to show the effectiveness of the 0-1 integer programming model. MATLAB simulation on a system employing M-ary quardarature amplitude modulation (MQAM) assuming a frequency-selective channel consisting of five independent Rayleigh multipaths are carried with the optimal subchannel and bit allocation solution generated by 0-1 integer programming model.
KeywordsPower Allocation Allocation Problem Channel Assignment Integer Programming Model Subchannel Allocation
- 1.Aggarwal, A., Meng, T.H.: A convex interior-point method for optimal OFDM PAR reduction. In: IEEE International Conference on Communications (ICC) (2005)Google Scholar
- 3.Kim, I., Lee, H.L., Kim, B., Lee, Y.H.: On the use of linear programming for dynamic subchannel and bit allocation in multiuser OFDM. In: GLOBECOM 2001, vol. 6, pp. 3648–3652 (2001)Google Scholar
- 4.Rhee, W., Cioffi, J.M.: Increasing in capacity of multiuser OFDM system using dynamic subchannel allocation. In: Proceedings of the IEEE VTC (2000)Google Scholar
- 5.Shen, Z., Andrews, J.G., Evans, B.L.: Optimal Power Allocation in Multiuser OFDM Systems. In: Proc. IEEE Global Comm. Conference, vol. 1, pp. 337–341 (2003)Google Scholar