Abstract
An upper bound is derived on the capacity of a cognitive radio system by considering the effects of path loss and log-normal shadowing simultaneously for a single-cell network. Assuming that the cognitive radio is informed only of the shadow fading between the secondary (cognitive) transmitter and primary receiver, the capacity is achieved via the water-filling power allocation strategy under an average primary signal to secondary interference plus noise ratio loss constraint. Contrary to the perfect channel state information requirement at the secondary system (SS), the transmit power control of the SS is accomplished in the absence of any path loss estimates. For this purpose, a method for estimating the instantaneous value of the shadow fading is also presented. A detailed analysis of the proposed power adaptation strategy is conducted through various numerical simulations.
Similar content being viewed by others
Notes
Section 4 discusses the approaches on how to estimate the instantaneous value of the shadow fading.
Contrary to the previous case, in this framework it is necessary that the secondary transmitter moves along the line connecting the secondary transmitter to primary receiver in order to express the total distance as \(d_0+d_i\)
References
Federal Communications Commission. (Nov. 2002). Spectrum policy task force. ET Docket No. 02–135, Technical Report.
Mitola, III, J., & Maguire, G.Q. (1999). Cognitive radio: Making software radios more personal. IEEE Personal Communications, 6(4) 13–18.
Haykin, S. (2005). Cognitive radio: Brain-empowered wireless communications. IEEE Journal on, Selected Areas in Communications, 23(2), 201–220.
Gastpar, M. (2007). On capacity under receive and spatial spectrum-sharing constraints. IEEE Transactions on, Information Theory, 53(2), 471–487.
Ghasemi, A., & Sousa, E. (2007). Fundamental limits of spectrum-sharing in fading environments. IEEE Transactions on Wireless Communications, 6(2), 649–658.
Goldsmith, A. J., & Varaiya, P. P. (1997). Capacity of fading channels with channel side information. IEEE Transactions on Information Theory, 43(6), 1986–1992.
Biglieri, E., Proakis, J., & Shamai, S. (1998). Fading channels: Information-theoretic and communications aspects. IEEE Transactions on Information Theory, 44(6), 2619–2692.
Liang, Y.-C., Zhang, R., & Cioffi, J. (2006). Subchannel grouping and statistical waterfilling for vector block-fading channels. IEEE Transactions on Communications, 54(6), 1131–1142.
Musavian, L., & Aissa, S. (2007). Ergodic and outage capacities of spectrum-sharing systems in fading channels. In Proceedings of the IEEE global telecommunication conference (GLOBECOM’07), pp. 3327–3331.
Kang, X., Liang, Y., Nallanathan, A., Krishna, H., & Zhang, R. (2009). Optimal power allocation for fading channels in cognitive radio networks: Ergodic capacity and outage capacity. IEEE Transactions on Wireless Communications, 8(2), 940–950.
Zhang, R., & Liang, Y.-C. (2008). Exploiting multi-antennas for opportunistic spectrum sharing in cognitive radio networks. IEEE Journal of Topics in Signal Processing, 2(1), 88–102.
Zhang, L., Liang, Y.-C., & Xin, Y. (2008). Joint beamforming and power allocation for multiple access channels in cognitive radio networks. IEEE Journal on Selected Areas in Communications, 26(1), 38–51.
Cho, H., & Andrews, J. (2009). Upper bound on the capacity of cognitive radio without cooperation. IEEE Transactions on Wireless Communications, 8(9), 4380–4385.
Vu, M., Devroye, N., Sharif, M., & Tarokh, V. (2007). Scaling laws of cognitive networks. In Proceedings of the international conference cognitive radio oriented wireless networks and communications (Crowncom), pp. 2–8.
Musavian, L., & Aissa S. (2008). Capacity of spectrum-sharing channels with minimum-rate requirements. In Proceedings of the IEEE international conference communications (ICC), pp. 4639–4643.
Chen, Y., Yu, G., Zhang, Z., Chen, H. H., & Qiu, P. (2008). On cognitive radio networks with opportunistic power control strategies in fading channels. IEEE Transactions on Wireless Communications, 7(7), 2752–2761.
Kang, X., Zhang, R., Liang, Y.-C., & Garg, H. K. (2011). Optimal power allocation strategies for fading cognitive radio channels with primary user outage constraint. IEEE Journal on Selected Areas in Communications, 29(2), 374–383.
Gong, X., Vorobyov, S., & Tellambura, C. (2011). Optimal bandwidth and power allocation for sum ergodic capacity under fading channels in cognitive radio networks. IEEE Transaction on Signal Processing, 59(4), 1814–1826.
Goldsmith, A. (2009). Wireless communications. Cambridge: Cambridge University Press.
ITU-R Recommendation M.1225. (1997). Guidelines for evaluation of radio transmission technologies for imt-2000.
IEEE P802.11 Wireless LANs. (2004). TGn channel models. IEEE 802.11-03/940r4.
Boyd, S., & Vandenberghe, L. (2004). Convex optimization. Cambridge: Cambridge University Press.
Algans, A., Pedersen, K. I., & Mogensen, P. E. (2002). Experimental analysis of the joint statistical properties of azimuth spread, delay spread, and shadow fading. IEEE Journal on Selected Areas in Communications, 20(3), 523–531.
Jalden, N., Zetterberg, P., Ottersten, B., & Garcia, L. (2007). Inter- and intrasite correlations of large-scale parameters from macrocellular measurements at 1800 mhz. EURASIP Journal on Wireless Communications and Networking, 2007, 12.
Rappaport, T. (1996). Wireless communications: Principles and practice. Upper Saddle River, NJ: Prentice-Hall Inc.
Hata, M. (1980). Empirical formula for propagation loss in land mobile radio service. IEEE Transactions on Vehicular Technology, 29, 317–325.
Poor, H. V. (1994). An introduction to signal detection and estimation. New York: Springer.
Stber, G. (2001). Principles of mobile communication (2nd ed.). Norwell, MA: Kluwer, Prentice-Hall Inc.
Tepedelenlioglu, C., Abdi, A., Giannakis, G. B., & Kaveh, M. (2001). Estimation of doppler spread and signal strength in mobile communications with applications to handoff and adaptive transmission. Wireless Communications and Mobile Computing, 1(2), 221–242.
Wong, D., & Cox, D. C. (1999). Estimating local mean signal power level in a rayleigh fading environment. IEEE Transactions on Vehicular Technology, 48(3), 956–959.
Goldsmith, A. J., Greenstein, L. J., & Foschini, G. J. (1994). Error statistics of real-time power measurements in cellular channels with multipath and shadowing. IEEE Transactions on Vehicular Technology, 43(3), 439–446.
Ko, Y. C., & Alouini, M. S. (2003). Estimation of nakagami-m fading channel parameters with application to optimized transmitter diversity systems. IEEE Transactions on Wireless Communications, 2(2), 250–259.
Jiang, T., Sidiropoulos, N. D., & Giannakis, G. B. (2003). Kalman filtering for power estimation in mobile communications. IEEE Transactions on Wireless Communications, 2(1), 151–161.
Dogandzic, A., & Zhang, B. (2005). Dynamic shadow-power estimation for wireless communications. IEEE Transactions on Signal Processing, 53(8), 2942–2948.
Fishman, G.S. (1996). Monte Carlo: Concepts, algorithms, and applications. Springer Series in Operations Research. New York: Springer.
Author information
Authors and Affiliations
Corresponding author
Appendix
Appendix
1.1 Derivation of Instantaneous SINR Loss at PS receiver
When no SS user is present in the PS service area, the SNR at the PS receiver can be written as
where \(P_p\) is the transmission power of the PS, \(G\left( r_{pp},\xi _{pp}\right) \) is the combined shadowing and path gain between PS transmitter and receiver, and \(N_p\) is the noise power at the PS receiver. When an SS transmitter is present and interferes with the PS receiver, the SINR at the PS receiver can be written as
where \(P_s\left( \mathbf{r}, \varvec{\xi } \right) \) is the transmission power of the SS and \(G\left( r_{sp},\xi _{sp}\right) \) is the combined shadowing and path gain between SS transmitter and PS receiver. From (33) and (34), the instantaneous SINR loss at the PS receiver due to the SS transmission is given as
Equation (35) indicates that \({\hbox {SINR}_{\mathrm{p,loss}}}\) depends on the interference level from the SS and the thermal noise at the PS victim, and it is independent of the PS tranmit power.
Rights and permissions
About this article
Cite this article
Dulek, B., Gezici, S., Sawai, R. et al. Power Adaptation for Cognitive Radio Systems Under an Average SINR Loss Constraint in the Absence of Path Loss Information. Wireless Pers Commun 77, 151–172 (2014). https://doi.org/10.1007/s11277-013-1499-8
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11277-013-1499-8