An iterative algorithm for interference detection and cancellation using multiple receiver antennas

Summary form only given. An iterative algorithm is presented to obtain the direction of arrival, magnitude, and phases of all desired and interference signals exist within a communication environment using a circular array of receiver antennas. The proposed method is able to detect all electromagnetic signals crossing through the receiver platform even if they have the same frequency and polarization so long as they are not in very close angular proximity compared to the receiver antenna beam-width. The algorithm operate in frequency domain and can handle wide bandwidth signals. In this method, initially the total time domain received signal at each receiver antenna is converted to the frequency domain using Fourier Transform. Then each complex signal component at all receiver antennas is used in the iterative algorithm to extract the direction of arrival, magnitude, and phase of both the desired and interference signals. Eventually the desired signal is extracted and converted to the time domain using Inverse Fourier Transform. Assuming a planar phase front for all signals arriving at the receiver array (sources and diffraction points are far from the scatterers), first, the space is swept to find the direction of arrival of the electromagnetic wave with the highest magnitude. To find this direction, the summation of the received signals from all receiver antennas after applying the optimum phase and magnitude weighting corresponding to all possible directions are calculated. Once this direction is found and the array is focused in that direction, the contribution of this signal at each receiver is estimated and subtracted from the total. This process is repeated until all signals arriving from all possible directions are estimated in the first iteration. In the next iterations, there are estimations for all signal directions, magnitudes, and phases. Therefore, more accurate solution is found as the number of the iterations is increased. This iterative algorithm i- continued until the difference between the obtained values for two consecutive iterations is less than a specified error value and eventually the solution converges. This procedure is done for all frequency components. This method is implemented to detect the desired communication signals in the presence of interferences and the simulation results show that this iterative algorithm provides excellent estimations of the directions of arrival, magnitudes, and phases of all signals.