DOA estimation method of broadband signal based on message passing algorithm

The invention discloses a DOA estimation method for a broadband signal based on a message passing algorithm. The DOA estimation method comprises the following steps: S1, constructing a statistical model according to a signal model; representing the joint distribution of the statistical model as a polynomial multiplication form according to a Bayesian chain rule; s2, marking polynomials as factor nodes, marking variables in each polynomial as variable nodes, and connecting the factor nodes and the variable nodes in sequence according to the distribution form of each polynomial, namely representing the statistical model as a factor graph form; s3, deriving an updating formula of the variable through a plurality of rules; and S4, performing updating iteration on different messages in sequence according to a message transmission sequence from an observation node, calculating confidence of each variable node so as to solve an estimated value of a variable, determining a position of a non-zero element according to