Novel Forward/Backward Signal Space for DOA Estimation of Coherent RF Signals

Direction of Arrival (DOA) estimation of multiple narrowband RF signals in multipath environments is crucial in real-time applications. In this paper, a novel method is presented to reduce the computational complexity of coherent signals in pairs while maintaining the estimation accuracy. The proposed method employs Cholesky decomposition in conjunction with a novel forward/backward operation (FBO) of the signal subspace matrix to de-correlate the incident signals while the existing methods apply spatial smoothing techniques to the covariance matrix. Employing FBO to the signal space along with Cholesky decomposition will significantly reduce the computational complexity and processing time. These advantages make the proposed method suitable for high-speed communication and real-time applications. Simulation results using Root Mean Square Error (RMSE) are presented to demonstrate the effectiveness of the proposed method and it is compared with Root-MUSIC method as a benchmark.