jamming reduction in gps receivers by subspace projection technique

different methods exists for jamming mitigation and we should choose a method based an the jammer type and other parameters. one of the jammers is narrow band fm jammer and we use subspace projection techniques for the suppression of this type of jammer. in subspace projection technique, we estimate the if of signals and construct the subspace vector that is orthogonal to jammer vector by increasing the number of antennas in the array; we enhance the performance of system. the subspace projection method was simulated in matlab and the receiver output sinr in several conditions was calculated. in the case of if estimation error, the sinr of the system is reduced; in this condition the use of an antenna array will increase the performance of the system compared to a single antenna.