Blind Channel Estimation Based on Adaptive Noise Subspace Estimation in WPT-CDMA System

Because noise subspace estimation for blind channel estimation can´t achieve a good trade-off between convergence speed and steady-state error, and an ambiguous complex coefficient exists between estimated and actual channel impulse response. In this paper, we propose a blind channel estimation algorithm based on noise subspace estimation algorithm with adaptive variable step-size and ambiguous complex coefficient identification technique to resolve these problems. In the meantime, combined with the advantages of wavelet packet orthogonality, we propose an algorithm of blind channel estimation based on noise subspace in multi-carrier CDMA with wavelet packet modulation (WPT-CDMA) system. The results of simulation show good channel estimation performance.