The modern radio communication solutions nowdays prefere software based processing. The SDR (Software Defend Radio) devices process the radio signals by software. This kind of approach can make really valuable operational functions, cause of its speed and flexibility. It is possible to locate the WiFi-connected device. The Wi-Fi software radio solution based on an FPGA, that provides an opportunity to process the sampled signals and to send forth through the Ethernet plug. The transmitter can locate in theory used by two-antenna module, that has been develop for the FPGA included SDR motherboard. Of course, the recieved signal processed after filtering, amplifying, downmixing, demodulating and analog – digital conversioning. Thus obtained digital signals has phase difference. The signal’s angle of incidence can approximatly can definable by the difference. The goal of this dissertation is to proof that the phase difference based localisation technique can realizable via the SDR environment.