OFDM for Cognitive Radio Systems: Novel Power Allocation and Bit Loading Algorithms

Authors

  • Shirin Razmi Department of Electrical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
  • Naser Parhizgar Department of Electrical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran

Abstract

A novel method to improve the performance of the frequency band is cognitive radio that was introduced in 1999. Due to a lot of advantages of the OFDM, adaptive OFDM method, this technique is used in cognitive radio (CR) systems, widely. In adaptive OFDM, transmission rate and power of subcarriers are allocated based on the channel variations to improve the system performance. This paper investigates adaptive resource allocation in the CR systems that are used OFDM technique to transmit data. The aim of this paper is to maximize the achievable transmission rate for the CR system by considering the interference constraint. Although secondary users can be aware form channel information between each other, but in some wireless standards, it is impossible for secondary user to be aware from channel information between itself and a primary user. Therefore, due to practical limitation, statistical interference channel is considered in this paper. This paper introduces a novel suboptimal power allocation algorithm. Also, this paper introduces a novel bit loading algorithm. In the numerical results sections, the performance of our algorithm is compared by optimal and conventional algorithms. Numerical results indicate our algorithm has better performance than conventional algorithms while its complexity is less than optimal algorithm.

References

C. B. A. Wael, N. Armi, M. T. Miftahushudur, “Power allocation in OFDM-based cognitive radio networks for fading channel,” International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications (ICRAMET), 2017.

J. Mitola, “Cognitive radio: an integrated agent architecture for software defined radio,” Ph.D. dissertation, Royal Inst. Technol., Stockholm, Sweden, 2000.

S. Pan, X. Zhao, Y. C. Liang, “Robust Power Allocation for OFDM-Based Cognitive Radio Networks: A Switched Affine Based Control Approach,” IEEE Access, vol. 5, 2017.

A. Karmokar, M. Naeem, A. Anpalagan, and Muhammad Jaseemuddin, “Energy-Efficient Power Allocation Using Probabilistic Interference Model for OFDM-Based Green Cognitive Radio Networks,”Journal of Energies, vol. 7, pp. 2535-2557, 2014.

W. Yang, X. Zhao, “Robust Relay Selection and Power Allocation for OFDM-Based Cooperative Cognitive Radio Networks,” IEEE Global Communications Conference (GLOBECOM), 2016.

Khederzadeh, R., Farrokhi, H. “Adaptive rate and power transmission in spectrum-sharing systems with statistical interference constraint,” IET Communications, vol. 6, pp. 870-877, 2014.

Musavian, L., Aissa, S., et al. “Adaptive Modulation in Spectrum-Sharing Channels Under Delay Quality-of-Service Constraints,” IEEE Transaction on vehicular, vol. 60, pp. 901-911, 2011.

R. K. Jangir, “Power allocation schemes for OFDM-based Cognitive Radio networks,” 2nd International Conference on Recent Advances in Engineering & Computational Sciences (RAECS), 2015.

Qaraqe, K. A., Bouida, Z., et al., “Performance Analysis of Joint Diversity Combining, Adaptive Modulation, and Power Control Schemes,” IEEE Transaction on communications, Vol. 59, pp. 106-115, 2011.

W.T. Webb and R. Steele, “Variable rate QAM for mobile radio,” IEEE Trans. Commun., vol. COM-43, pp. 2223-2230, 1995.

Khederzadeh, R, Hasanvand, A. J., Farrokhi, H., “Resource Management in Spectrum Sharing Cognitive Radio Networks with Probabilistic Interference Constraints,” The 22nd Iranian Conference on Electrical Engineering, (ICEE 2014), 2014.

T. L. Van, H. D. Chi, K. N. Viet, H.N. Thanh, “Full-Filling Subcarrier Power Allocation in OFDMA-Based Cognitive Radio Systems,” Wireless Engineering and Technology, vol. 5, pp. 11-18, 2014.

Khederzadeh, R, Farrokhi, H., “Optimal and Suboptimal Adaptive Algorithms for Rate and Power Transmission in OFDM-Based Cognitive Radio Systems,” Computers & Electrical Engineering journal, vol. 42, pp 168-177, 2015.

Zhao, C., Kwak, K.: ‘Power/Bit loading in OFDM-based cognitive networks with comprehensive interference considerations: the single-SU case’, IEEE Transactions on Vehicular Technology, Vol. 59, pp. 1910-1922, 2010.

Bansal, G., Hossain, M. J., Bhargava, V. K. “Optimal and suboptimal power allocation schemes for OFDM-based cognitive radio systems,” IEEE Transactions on Wireless Communications, vol. 7, pp. 4710-4718, 2008.

Bansal, G., Hossain, J., Bhargava, V. K., “Adaptive power loading for OFDM-based cognitive radio systems with statistical interference constraint,” IEEE Transactions on Wireless Communications, vol. 10, pp. 2786-2791, 2011.

Zhang, Y., Leung, C., “An efficient power-loading scheme for OFDM-based cognitive radio systems,” IEEE Transactions on Vehicular Technology’, vol. 59, pp. 1858-1864, 2010.

E. Bedeer, O. A. Dobre, M. H. Ahmed, and K. E. Baddour, “Adaptive Rate and Power Transmission for OFDM-based Cognitive Radio Systems,” Signal Processing for Communications Symposium, IEEE ICC 2013.

Chung, S. T., Goldsmith, A. J. “Degrees of freedom in adaptive modulation: a unified view,” IEEE Transactions on Communications, Vol. 49, pp. 1561-1571, 2001.

V. Thumar, T. Nadkar, T. Gopavajhula, U.B. Desai and S. N. Merchant, “Power allocation, bit loading and sub-carrier bandwidth sizing for OFDM-based cognitive radio,” Journal on Wireless Communications and Networking, 2011.

R. V. Sonalkar and R. R. Shively. “An efficient bit-loading algorithm for DMT applications,” IEEE Communication Letter, vol. 4, pp. 80–82, 2000.

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Published

2019-02-16

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Section

Telecommunications