Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems

Nguyen Van Vinh; Pham Ngoc Thang

doi:doi:10.11648/j.ajnc.20140304.11

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Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems

Nguyen Van Vinh, Pham Ngoc Thang

Published in American Journal of Networks and Communications (Volume 3, Issue 4)

Received: 29 July 2014 Accepted: 15 August 2014 Published: 30 September 2014

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Abstract

Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this case, a sub-optimal power allocation algorithm based on power function distribution is proposed, to allocate power of in-band subcarrier of cognitive user according to the numerical characteristics of the power function by using a convex optimization numerical method under linear constraint. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference for the authorized user brought by the power leakage of the in-band subcarrier of cognitive user appears in the out-of-band. MALAB simulation results show that the proposed scheme maximizes the in-band channel capacity of the cognitive user under the interference threshold of the authorized user and the comparison model the optimal relationship between the limited and unlimited transmit power capacity. Meanwhile, the maximum transmission rate of the existing power allocation scheme is increased within the same condition.

Published in	American Journal of Networks and Communications (Volume 3, Issue 4)
DOI	10.11648/j.ajnc.20140304.11
Page(s)	49-55
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2014. Published by Science Publishing Group

Keywords

Orthogonal Frequency-Division Multiplexing (OFDM), Cognitive Radio (CR), Power Allocation, Linear Water-Filling, Convex Optimization

References

[1]	S. Haykin, Simon, “Cognitive radio: Brain-Empowered Wireless Communications,” IEEE Journal on Selected Areas in Communications, vol. 23, pp. 201-220, 2005.
[2]	Akyildiz I. F., Won-YeoI Lee, Vuran Mehmet C., Mohanty S., “Next generation, dynamic spectrum access, cognitive radio wireless networks, a survey,” Computer Networks of Elsevier, vol. 46, pp. 40-48, April. 2008.
[3]	Weiss T. A., Jondral F. K., Spectrum pooling, “An innovative strategy for the enhancement of spectrum efficiency,” Communications Magazine of IEEE, vol. 42, pp. S8-14, 2004.
[4]	Weiss T., Hillenbrand J., Krohn A., Jondral, F.K, “Mutual interference in OFDM-based spectrum pooling Systems,” Proc. IEEE Vehicular Technology Conferenc Spring, IEEE Press, vol. 4, pp. 1873-1877, 2004.
[5]	Bansal G., Hossain 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.
[6]	Wyglinski, Alexander M., “Effects of bit allocation on non-contiguous multicarrier-based cognitive radio transceivers,” Proceeding of Vehicular Technology Conference of the IEEE, pp. 1-5, 2006.
[7]	G. Bansal, M. J. Hossain, V. K. Bhargava, “A daptive power loading for OFDM-based cognitive radio systems”, Proc IEEE ICC, IEEE Press, pp. 5137-5142, 2007.
[8]	G. J. Foschini and J. Salz, “Digital communications over fading radio channels,” Bell Syst. Tech. J., pp. 429-456, Feb. 1983.
[9]	Wang P, Zhao M, Xiao L, “Power allocation in OFDM-based cognitive radio systems”, Proc. IEEE Global Communication Conference, IEEE Press, pp. 4061-4065, 2007.
[10]	Nguyen Van Vinh, Yang Shouyi and Le Chung Tran, “Power Allocation Algorithm in OFDM-Based Cognitive Radio Systems,” Proc. IEEE ComManTel Conf., IEEE Press, pp. 13-18, April 2014.

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APA Style

Nguyen Van Vinh, Pham Ngoc Thang. (2014). Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. American Journal of Networks and Communications, 3(4), 49-55. https://doi.org/10.11648/j.ajnc.20140304.11

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ACS Style

Nguyen Van Vinh; Pham Ngoc Thang. Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. Am. J. Netw. Commun. 2014, 3(4), 49-55. doi: 10.11648/j.ajnc.20140304.11

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AMA Style

Nguyen Van Vinh, Pham Ngoc Thang. Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. Am J Netw Commun. 2014;3(4):49-55. doi: 10.11648/j.ajnc.20140304.11

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@article{10.11648/j.ajnc.20140304.11,
  author = {Nguyen Van Vinh and Pham Ngoc Thang},
  title = {Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems},
  journal = {American Journal of Networks and Communications},
  volume = {3},
  number = {4},
  pages = {49-55},
  doi = {10.11648/j.ajnc.20140304.11},
  url = {https://doi.org/10.11648/j.ajnc.20140304.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajnc.20140304.11},
  abstract = {Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this case, a sub-optimal power allocation algorithm based on power function distribution is proposed, to allocate power of in-band subcarrier of cognitive user according to the numerical characteristics of the power function by using a convex optimization numerical method under linear constraint. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference for the authorized user brought by the power leakage of the in-band subcarrier of cognitive user appears in the out-of-band. MALAB simulation results show that the proposed scheme maximizes the in-band channel capacity of the cognitive user under the interference threshold of the authorized user and the comparison model the optimal relationship between the limited and unlimited transmit power capacity. Meanwhile, the maximum transmission rate of the existing power allocation scheme is increased within the same condition.},
 year = {2014}
}

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TY  - JOUR
T1  - Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems
AU  - Nguyen Van Vinh
AU  - Pham Ngoc Thang
Y1  - 2014/09/30
PY  - 2014
N1  - https://doi.org/10.11648/j.ajnc.20140304.11
DO  - 10.11648/j.ajnc.20140304.11
T2  - American Journal of Networks and Communications
JF  - American Journal of Networks and Communications
JO  - American Journal of Networks and Communications
SP  - 49
EP  - 55
PB  - Science Publishing Group
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UR  - https://doi.org/10.11648/j.ajnc.20140304.11
AB  - Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this case, a sub-optimal power allocation algorithm based on power function distribution is proposed, to allocate power of in-band subcarrier of cognitive user according to the numerical characteristics of the power function by using a convex optimization numerical method under linear constraint. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference for the authorized user brought by the power leakage of the in-band subcarrier of cognitive user appears in the out-of-band. MALAB simulation results show that the proposed scheme maximizes the in-band channel capacity of the cognitive user under the interference threshold of the authorized user and the comparison model the optimal relationship between the limited and unlimited transmit power capacity. Meanwhile, the maximum transmission rate of the existing power allocation scheme is increased within the same condition.
VL  - 3
IS  - 4
ER  -

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Author Information

Nguyen Van Vinh

School of Information Engineering, Zhengzhou University, China
Pham Ngoc Thang

Faculty of Electronic and Electrical Engineering, Hung Yen University of Technology and Education, Hung Yen, Vietnam

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APA Style

Nguyen Van Vinh, Pham Ngoc Thang. (2014). Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. American Journal of Networks and Communications, 3(4), 49-55. https://doi.org/10.11648/j.ajnc.20140304.11

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ACS Style

Nguyen Van Vinh; Pham Ngoc Thang. Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. Am. J. Netw. Commun. 2014, 3(4), 49-55. doi: 10.11648/j.ajnc.20140304.11

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AMA Style

Nguyen Van Vinh, Pham Ngoc Thang. Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems. Am J Netw Commun. 2014;3(4):49-55. doi: 10.11648/j.ajnc.20140304.11

Copy | Download

@article{10.11648/j.ajnc.20140304.11,
  author = {Nguyen Van Vinh and Pham Ngoc Thang},
  title = {Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems},
  journal = {American Journal of Networks and Communications},
  volume = {3},
  number = {4},
  pages = {49-55},
  doi = {10.11648/j.ajnc.20140304.11},
  url = {https://doi.org/10.11648/j.ajnc.20140304.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajnc.20140304.11},
  abstract = {Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this case, a sub-optimal power allocation algorithm based on power function distribution is proposed, to allocate power of in-band subcarrier of cognitive user according to the numerical characteristics of the power function by using a convex optimization numerical method under linear constraint. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference for the authorized user brought by the power leakage of the in-band subcarrier of cognitive user appears in the out-of-band. MALAB simulation results show that the proposed scheme maximizes the in-band channel capacity of the cognitive user under the interference threshold of the authorized user and the comparison model the optimal relationship between the limited and unlimited transmit power capacity. Meanwhile, the maximum transmission rate of the existing power allocation scheme is increased within the same condition.},
 year = {2014}
}

Copy | Download

TY  - JOUR
T1  - Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems
AU  - Nguyen Van Vinh
AU  - Pham Ngoc Thang
Y1  - 2014/09/30
PY  - 2014
N1  - https://doi.org/10.11648/j.ajnc.20140304.11
DO  - 10.11648/j.ajnc.20140304.11
T2  - American Journal of Networks and Communications
JF  - American Journal of Networks and Communications
JO  - American Journal of Networks and Communications
SP  - 49
EP  - 55
PB  - Science Publishing Group
SN  - 2326-8964
UR  - https://doi.org/10.11648/j.ajnc.20140304.11
AB  - Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this case, a sub-optimal power allocation algorithm based on power function distribution is proposed, to allocate power of in-band subcarrier of cognitive user according to the numerical characteristics of the power function by using a convex optimization numerical method under linear constraint. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference for the authorized user brought by the power leakage of the in-band subcarrier of cognitive user appears in the out-of-band. MALAB simulation results show that the proposed scheme maximizes the in-band channel capacity of the cognitive user under the interference threshold of the authorized user and the comparison model the optimal relationship between the limited and unlimited transmit power capacity. Meanwhile, the maximum transmission rate of the existing power allocation scheme is increased within the same condition.
VL  - 3
IS  - 4
ER  -

Copy | Download