Impact of jammers on the CRLB of the SOI estimation

From the forging figures, we can generally come to the following conclusions (1) The strength of a jammer will not influence much on CRLB of the absolute amplitude of the SOI. (2) The arriving direction of a jammer has impact on the CRLB of the absolute amplitude of the SOI. The nearer its arriving angle is to that of the SOI, the larger the impact will be and consequentially, the estimated solution will be worse. (3) The quantity of incoming jammers also has impact on the CRLB of the absolute amplitude of the SOI. More jammers coherent with the SOI, the larger the impact will be and consequentially, the estimated solution will be worse. (4) No matter how affected the CRLB is by jammers, we can always diminish this effect by increasing the number of antenna elements. It is because more receiving elements will produce more accurate estimation results. Although we focus only on the CRLB of the absolute amplitude of the SOI, we can reach similar conclusions on the CRLB of other parameters of the SOI such as its initial phase and arriving direction, which are not discussed in this paper.