A novel on off antenna-array algorithm for CDMA mobile communications systems

This paper presents a new modified on-off algorithm version for adaptive antenna arrays for CDMA communication systems. Two approaches are proposed: one uses a new variable step size algorithm termed as the variable on off (VOO), and the second employs step size intervals to ensure a good tracking of the desired user maximum power as well as fast convergence. This second approach is called the modified variable on off algorithm (MVOO). By using a geometric-based stochastic channel model (GBSBEM), numerical simulations were carried out to perform comparisons between the conventional on-off (COO) , the VOO and MVOO algorithms. The advantages of the two latter schemas over the COO-based system consist in a sensitive increasing in system capacity and an important reduction of time convergence. The MVOO shows the best performances at the expense of a relative hardware complexity.