Channel estimation method and system for precision-complexity joint optimization of underwater acoustic OFDM (Orthogonal Frequency Division Multiplexing) system

The invention discloses a channel estimation method and system for precision-complexity joint optimization of an underwater acoustic OFDM (Orthogonal Frequency Division Multiplexing) system, and belongs to the technical field of underwater acoustic wireless communication. According to the method, two termination conditions are designed according to different signal-to-noise ratio conditions: based on the distribution characteristic of additive noise of the UWA-OFDM communication system, a termination condition which only depends on noise power is deduced, and the termination condition is suitable for the low signal-to-noise ratio condition; and another suitable termination condition is designed by combining the power ratio of an observation vector to a residual vector, and the method is suitable for a high signal-to-noise ratio condition. Compared with a traditional OMP algorithm, the method has the advantages that accurate estimation of channel state information can be achieved with extremely low calculation