Reduction of multi-path effect based on correlation decomposition in a DOA estimation system

Abstract

The multi-path phenomenon is one of the main causes of error in Direction Of Arrival Estimation systems which are located in a complex environment. The received signal in this environment consists of Line Of Sight (LOS) and multi-path components which are delayed versions of the LOS signal with the amplitude and the phase depending on the path length. In order to eliminate the multi-path signal, it is necessary to estimate the amplitude, the phase, and the delay of the signal. To this end, a method based on correlation which has been already used to estimate amplitudes and delays of Line Of Sight and multi-path signals in GPS systems, is implemented. After this estimation process, a phase estimation algorithm is proposed in order to construct the multi-path signal replica adequately. Finally, by subtracting the estimated multi-path component from the total signal, the LOS component could be extracted. Simulations show that this algorithm eliminates adequately the multi-path component and results in a better DOA estimation.