Three novel simple beamforming algorithms for CDMA communication systems
Farhad Tavassoli, Bahman Abolhassani, Homayoon Oraizi, Chi Zhou · International Journal of Communication Systems · 2012
SUMMARY To apply a beamforming algorithm with a linear array ofNantennas 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 2N–1 complex additions and either 2N+1 or 2Ncomplex 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 ifNis restricted.Copyright © 2012 John Wiley & Sons, Ltd.