Blind MIMO channel estimation with an upper bound for channel orders

Many known second-order statistics based blind algorithms for MIMO channel estimation are sensitive to channel order overestimations. To overcome this problem, an algorithm is proposed in [1] for SIMO system only, and then a simple generalization of it to MIMO system is presented in [2]. In this paper, improvements and refinements on the algorithm in [2] are given, which makes the method robust to noise and round-off error. The method can give estimations of all channel impulse responses subject to a scalar matrix ambiguity when only an upper bound for all MIMO channel orders is known.