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Three novel simple beamforming algorithms for CDMA communication systems
Author(s) -
Tavassoli Farhad,
Abolhassani Bahman,
Oraizi Homayoon,
Zhou Chi
Publication year - 2014
Publication title -
international journal of communication systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.344
H-Index - 49
eISSN - 1099-1131
pISSN - 1074-5351
DOI - 10.1002/dac.2358
Subject(s) - computer science , algorithm , beamforming , simple (philosophy) , code division multiple access , rayleigh fading , adaptive beamformer , smart antenna , wireless , fading , telecommunications , decoding methods , directional antenna , antenna (radio) , philosophy , epistemology
SUMMARY To apply a beamforming algorithm with a linear array of N antennas in real wireless communication systems, two main issues should be addressed: Algorithm complexity and number of antennas. In this paper, we propose three simple beamforming algorithms for direct sequence code division multiple access systems. We first propose a new framework to obtain the updating equation for the weight vector using PCA. Then, using this framework, four different objective functions are used as examples to illustrate how to obtain new adaptive algorithms. We demonstrate that these objective functions lead to three novel blind algorithms, with two of them resulting in the same algorithm. Moreover, they have considerably low complexities, requiring only 2 N –1 complex additions and either 2 N +1 or 2 N complex multiplications for a single run. We evaluate the performances of these algorithms in estimating the angle‐of‐arrival of the desired signal and in producing the array beam pattern, and in alleviating the BER in Rayleigh fading and AWGN channels. In summary, these new beamforming algorithms obtained based on the proposed framework operate as blind algorithms, have low computational complexities, and offer desirable performances even if N is restricted.Copyright © 2012 John Wiley & Sons, Ltd.