Abstract:

This paper studies multi-user detection for CDMA downlink and proposes a new approach for blind detection to overcome multi-access interference (MAI) in CDMA systems. The method is called linear constraint conjugate gradient constant modulus algorithm based on adaptive step size. The best step size is used to achieve optimization. An analytical form is obtained. Simulations for additive white Gaussian channel and multi-path fading channel environments show that the proposed technique can provide SIR and BER improvement with respect to other adaptive step size CMA.

Key words:

linear constraint, conjugate gradient, constant modulus algorithm, optimum step size