Interference Management for DS-CDMA Systems through Closed-Loop Power Control, Base Station Assignment, and Beamforming

Mohamad Dosaranian Moghadam, Hamidreza Bakhshi, Gholamreza Dadashzadeh
DOI: 10.4236/wsn.2010.26059                

Abstract

In this paper, we propose a smart step closed-loop power control (SSPC) algorithm and a base station assignment method based on minimizing the transmitter power (BSA-MTP) technique in a direct sequence-code division multiple access (DS-CDMA) receiver with frequency-selective Rayleigh fading. This receiver consists of three stages. In the first stage, with constrained least mean squared (CLMS) algorithm, the desired users’ signal in an arbitrary path is passed and the inter-path interference (IPI) is reduced in other paths in each RAKE finger. Also in this stage, the multiple access interference (MAI) from other users is reduced. Thus, the matched filter (MF) can use for more reduction of the IPI and MAI in each RAKE finger in the second stage. Also in the third stage, the output signals from the matched filters are combined according to the conventional maximal ratio combining (MRC) principle and then are fed into the decision circuit of the desired user. The simulation results indicate that the SSPC algorithm and the BSA-MTP technique can significantly reduce the network bit error rate (BER) compared to the other methods. Also, we observe that significant savings in total transmit power (TTP) are possible with our methods.

Keywords

Adaptive Beamforming, Antenna Array, Base Station Assignment, Closed-Loop Power Control, Constrained LMS, DS-CDMA

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	A. Abrardo and D. Sennati, “On the Analytical Evaluation of Closed-Loop Power-Control Error Statistics in DS-CDMA Cellular Systems,” IEEE Transactions on Vehicular Technology, Vol. 49, No. 6, 2000, pp. 2071- 2080.
[2]	L. Carrasco and G. Femenias, “Reverse Link Perform- ance of a DS-CDMA System with Both Fast and Slow Power Controlled Users,” IEEE Transactions on Wireless Communications, Vol. 7, No. 4, 2008, pp. 1255-1263.
[3]	L. Qian and Z. Gajic, “Variance Minimization Stochastic Power Control in CDMA System,” IEEE Transactions on Wireless Communications, Vol. 5, No. 1, 2006, pp. 193- 202.
[4]	M. Rintamaki, H. Koivo and I. Hartimo, “Adaptive Closed- Loop Power Control Algorithms for CDMA Cellular Communication Systems,” IEEE Transactions on Vehicular Technology, Vol. 53, No. 6, 2004, pp. 1756-1768.
[5]	J. Wang and A. Yu, “Open-Loop Power Control Error in Cellular CDMA Overlay Systems,” IEEE Journal on Selected Areas in Communications, Vol. 19, No. 7, 2001, pp. 1246-1254.
[6]	J. T. Wang, “Admission Control with Distributed Joint Diversity and Power Control for Wireless Networks,” IEEE Transactions on Vehicular Technology, Vol. 58, No. 1, 2009, pp. 409-419.
[7]	M. Dosaranian-Moghadam, H. Bakhshi, G. Dadashzadeh and P. Rahmati, “Adaptive Beamforming Method Based on Constrained LMS Algorithm for Tracking Mobile User,” IEEE Global Mobile Congress, Shanghai, October 2009, pp. 1-6.
[8]	J. Chang, L. Tassiulas and F. Rashid-Farrokhi, “Joint Transmitter Receiver Diversity for Efficient Space Division Multiaccess,” IEEE Transactions on Wireless Communications, Vol. 1, No. 1, 2002, pp. 16-27.
[9]	N. A. Mohamed and J. G. Dunham, “A Low-Complexity Combined Antenna Array and Interference Cancellation DS-CDMA Receiver in Multipath Fading Channels,” IEEE Journal on Selected Areas in Communications, Vol. 20, No. 2, 2002, pp. 248-256.
[10]	N. A. Mohamed and J. G. Dunham, “Adaptive Beamforming for DS-CDMA Using Conjugate Gradient Algorithm in a Multipath Fading Channel,” Proceedings of 1999 IEEE Emerging Technologies Symposium, Dallas, April 1999, pp. 859-863.
[11]	F. Rashid-Farrokhi, K. J. Ray-Liu and L. Tassiulas, “Transmit Beamforming and Power Control for Cellular Systems,” IEEE Journal on Selected Areas in Communications, Vol. 16, No. 8, 1998, pp. 1437-1450.
[12]	F. Rashid-Farrokhi, L. Tassiulas and K. J. Ray-Liu, “Joint Optimal Power Control and Beamforming in Wireless Networks Using Antenna Arrays,” IEEE Transactions on Communications, Vol. 46, No. 10, 1998, pp. 1313-1324.
[13]	R. D. Yates and C. Huang, “Integrated Power Control and Base Station Assignment,” IEEE Transactions on Vehicular Technology, Vol. 44, No. 3, 1995, pp. 638-644.
[14]	S. V. Hanly, “An Algorithm for Combined Cell-Site Selection and Power Control to Maximize Cellular Spread Spectrum Capacity,” IEEE Journal on Selected Areas in Communications, Vol. 13, No. 7, 1995, pp. 1332-1340.
[15]	M. Mahmoudi and E. S. Sousa, “Joint Power Control, Base Station Assignment and Sectorization for CDMA Cellular Systems,” Proceedings of 2000 IEEE Vehicular Technology Conference, Boston, September 2000, pp. 573-580.
[16]	J. Litva and T. Kwok-Yeung, “Digital Beamforming in Wireless Communications,” Artech House, Boston, 1996.
[17]	X. Y. Sun, X. H. Lian and J. J. Zhou, “Robust Adaptive Beamforming Based on Maximum Likelihood Estimation,” International Conference on Microwave and Millimeter Wave Technology, Nanjing, April 21-24, 2008, pp. 1137- 1140.
[18]	M. Z. Shakir and T. S. Durrani, “Narrowband Beamforming Algorithm for Smart Antennas,” International Bhurban Conference on Applied Sciences & Technology, Islamabad, Pakistan, January 2007, pp. 49-54.
[19]	S. Haykin, “Adaptive Filter Theory,” 3rd Edition, Prentice Hall, New Jersey, 1996.
[20]	R. L. Peterson, R. E. Ziemer and D. E. Borth, “Spread- Spectrum Communications,” Prentice-Hall, New Jersey, 1995.
[21]	N. Kong and L. B. Milstein, “Average SNR of a GeneralIzed Diversity Selection Combining Scheme,” IEEE Commu- nications Letters, Vol. 3, No. 3, 1999, pp. 57-59.
[22]	J. C. Liberti and T. S. Rappaport, “Smart Antennas for Wireless Communications IS-95 and Third Generation CDMA Applications,” Prentice-Hall, New Jersey, 1999.
[23]	A. Yener, R. D. Yates and S. Ulukus, “Interference Management for CDMA Systems through Power Control, Multiuser Detection, and Beamforming,” IEEE Transactions on Communications, Vol. 49, No. 9, 2001, pp. 1227-1239.
[24]	S. Grandhi, R. Vijayan and D. Goodman, “Centralized Power Control in Cellular Radio Systems,” IEEE Transactions on Vehicular Technology, Vol. 42, No. 4, 1993, pp. 466-468.
[25]	S. Grandhi, R. Vijayan and D. Goodman, “Distributed Power Control in Cellular Radio Systems,” IEEE Transactions on Communications, Vol. 42, No. 2-4, 1994, pp. 226-228.
[26]	A. Kurniawan, “Effect of Feedback Delay on Fixed Step and Variable Step Power Control Algorithm in CDMA Systems,” The 8th International Conference on Communication Systems, Indonesia, 2002, pp. 1096-1100.
[27]	B. Allen and M. Beach, “On the Analysis of Switched- beam Antennas for the W-CDMA Downlink,” IEEE Tra- nsactions on Vehicular Technology, Vol. 53, No. 3, 2004, pp. 569-578.