Title :
High performance antenna array algorithm for DS/CDMA communications
Author :
Liu, Shang-Chieh ; Geraniotis, Evaggelos
Author_Institution :
Dept. of Electr. Eng., Maryland Univ., College Park, MD, USA
Abstract :
We propose a new beamforming method, which is based on eigenvalue decomposition and interference cancellation (EDIC), for the RAKE structure antenna array in DS/CDMA communication systems such as IS-95 or PCS. Our approach uses the desired signature code and the orthogonal code to decompose the receiving signals into two parts: the desired signal and interference. The beamforming weights are blindly updated according to these two sub-spaces. Unlike the null space beamforming method, the new beamformer can handle a large number of users with a small number of antenna elements. To adapt to the time varying environment, a recursive algorithm is developed at a very low hardware complexity. Monte Carlo simulations show that the new blind recursive algorithm converges very fast and has better performance than the well known generalized eigenvalue decomposition (GED) method
Keywords :
adaptive antenna arrays; adaptive signal processing; array signal processing; cellular radio; code division multiple access; convergence of numerical methods; direction-of-arrival estimation; eigenvalues and eigenfunctions; interference suppression; land mobile radio; personal communication networks; pseudonoise codes; radio links; radiofrequency interference; spread spectrum communication; time-varying channels; DS/CDMA communications; IS-95; Monte Carlo simulations; PCS; RAKE structure; antenna elements; beamforming method; beamforming weights; blind recursive algorithm; convergence; eigenvalue decomposition; generalized eigenvalue decomposition; high performance antenna array algorithm; interference cancellation; low hardware complexity; null space beamforming method; orthogonal code; performance; receiving signals decomposition; recursive algorithm; signature code; time varying environment; uplink; Antenna arrays; Array signal processing; Covariance matrix; Eigenvalues and eigenfunctions; Filters; Interference; Matrix decomposition; Propagation delay; Signal to noise ratio; White noise;
Conference_Titel :
Vehicular Technology Conference, 1997, IEEE 47th
Conference_Location :
Phoenix, AZ
Print_ISBN :
0-7803-3659-3
DOI :
10.1109/VETEC.1997.600515