Blind estimation of space-time coded systems using the finite alphabet-constant modulus algorithm

Space-time coding introduces spatial and temporal correlations into signals transmitted from multiple antennas in order to provide diversity and coding gain at the receiver. In the field of blindly estimating space-time coded signals impinging on an antenna array, an effective scheme for jointly exploring the constant modulus (CM) and the finite alphabet (FA) constraints is presented. The CM constraints are explored algebraically, whereas the FA constraints are explored via an iterative algorithm considering the constraints imposed by the space-time coded signals. This leads to our novel FACM algorithm that offers a wide range of trade-offs between performance and complexity while it lends itself to an amenable (step-by-step) algorithmic implementation as well as an amenable algorithmic complexity