Blind channel estimation for multiuser CDMA systems with long spreading codes

In this paper, correlation-matching techniques are employed to estimate multipath channel parameters for a multiuser CDMA system with long spreading codes. For a given code sequences, the output correlation matrix (parametrized by the unknown channel coefficients) is compared with its instantaneous approximation. By minimizing the Frobenious norm of the resulting error matrix the channel parameters can be estimated up to a scalar ambiguity. Under the assumption of i.i.d. code sequences, identifiability for each channel is guaranteed and the asymptotic convergence of the proposed algorithm is established. Simulation results confirm our claims. Comparisons with other methods are also provided