A New CMA Algorithm for Adaptive Array Systems with Rayleigh Channel Fading in the Mobile Communications Based on CDMA
Subject Areas : electrical and computer engineering
E.
Jedari
1
Mohammad
Hakkak
2
(Tarbiat Modares University)
M.
Kamarei
3
(استاد دانشگاه تهران)
Keywords: Adaptive array antennasbeam formingCDMAvector channelVS-CMA,
Abstract :
In this paper, we propose a time-varying multi-path vector channel model for the cellular CDMA-based communication system environment. A modified CMA to use in CDMA system environment is presented. We assume that the angular spread of each source to be large so that fading is non-coherent across the elements of the antenna array. The proposed modified CMA algorithm is more suitable in studying the convergence performance and the radiation patterns of uniform linear for tracking signal sources in CDMA mobile systems. Comparing the signal to noise ratio at the output of the algorithm of a uniform linear with the theoretical results proves the efficiency of the proposed algorithm. The BER performance with DBPSK modulation is also compared for CMA and VS-CMA algorithms in linear array.
[1] R. Gooch and J. Lundell, "The CMA array: an adaptive beamformer for constant modulus signals," in Proc. IEEE ICASSP, vol. 4, pp. 2523-2526, Apr. 1980.
[2] J. R. Treichler and B. G. Agee, "A new approach to multipath correction of constant modulus signals," IEEE Trans. on Acoustics, Speech, and Signal Processing, vol. 31, no. 2, pp. 459-471, Apr. 1983.
[3] J. R. Treichler and M. G. Larimore, "New processing techniques based on the constant modulus adaptive algorithm," IEEE Trans. on Acoustics, Speech, and Signal Processing, vol. 33, no. 2, pp. 420-431, Apr. 1985.
[4] T. Ohgare, "Characteristics of CMA adaptive array for selective fading compensation in digital land mobile radio communication," Electronics and Communications in Japan, pt. I, vol. 74, no. 9, pp. 43-53, Sept. 1991.
[5] غ. داداش‌زاده، م. بيغش، م. حکاک و م. کمره‌اي، "بررسي همبستگي سيگنال CDMA دريافتي در کانال مخابرات سيار سلولي روي المان‌هاي آنتن آرايه‌اي،" مجله بين المللي علوم مهندسي، جلد 14، شماره 5، سال 1382، صص 61-41، دانشگاه علم و صنعت ايران.
[6] J. J. Shynk and R. P. Gooch, "The constant modulus array for co-channel signal copy and direction finding," IEEE Trans. on Signal Processing, vol. 44, no. 5, pp. 652-660, Mar. 1996.
[7] J. J. Shynk, A. V. Keerlhi, and A. Mathur, "Steady-state analysis for the multistage constant modulus array," IEEE Trans. on Signal Processing, vol. 44, no. 4, pp. 948-962, Apr. 1996.
[8] A. Mathur, A. Keerthi, and J. J. Shynk, "A variable step-size CMA array algorithm for fast fading channels," IEEE Trans. on Signal Processing, vol. 45, no. 4, Apr. 1997.
[9] م. بيغش، بررسي كاربرد پردازش آرايه‌اي درمخابرات سيار به منظور ردگيري واحد مخابراتي و تضعيف لوبهاي فرعي آنتن آرايه، پايان‌نامه دكترا، دانشگاه صنعتي شريف، 1379.
[10] Z. Zhimin and Q. Ianfen, "The CMA adaptive for CDMA cellular communication systems," in Proc. CEEM’2000, pp. 163-166, Shanghai, China, May 2000.
[11] J. G. Proakis, Digital Communication, McGraw-Hill, 1995.
[12] J. C. Liberti and T. S. Rappaport, "Analytical result for reverse channel performance improvement in CDMA cellular communication systems employing adaptive antennas," in Proc. IEEE Globecom’93, pp. 42-47, 1993.