1. A method for low complexity maximum likelihood sequence detection, comprising: computing, with a decision feedback detector, x(M+D+L−1) using a decision feedback algorithm, wherein x is a signal sequence, M is a running index of a window center, D is a predetermined constant, and L is a memory parameter; performing, with an optimality examiner, optimality examination for x(M); and computing state values and values of Markov states along paths from states in x(M) to x(M+L).