A system for localizing a transmitting wireless device (210; 510; 511) within a known volume, the system comprising: N > = 2 antennae (203, 204, 205; 301; 500, 501) deployed in N > = 2 respective locations at least some of which are located within the known volume, each of the antennae being operative to receive and output a signal (213, 214, 215; 520, 521; 522, 523) from the transmitting wireless device; at least one analog-to-digital converter operative to convert analog received signals at the output of the antennae to digital sampled received signals; and a processor operative: to receive said digital sampled received signals and to compute at least one real time output parameter comprising a predetermined function of: digitally sampled received signals S, received from the transmitting wireless device at antenna i; and of digitally sampled signals, received from the transmitting wireless device at antenna j and digitally sampled, simultaneously with reception at antenna i and digital sampling of said digitally sampled received signals S, which predetermined function is independent of a power level at which the transmitting device is transmitting, and to estimate the transmitting wireless device's location within the volume by comparing said at least one real time output parameter to plural reference output parameters respectively having a known correspondence to plural known possible locations within said volume respectively, for at least one pair of antennae i, j from among said N antennae, characterized in that said predetermined function comprises a probability density function of a ratio between: quality of reception of transmission from the transmitting wireless device at antenna i; and simultaneous quality of reception of transmission from the transmitting wireless device at antenna j. N > = 2 antennae (203, 204, 205; 301; 500, 501) deployed in N > = 2 respective locations at least some of which are located within the known volume, each of the antennae being operative to receive and output a signal (213, 214, 215; 520, 521; 522, 523) from the transmitting wireless device; at least one analog-to-digital converter operative to convert analog received signals at the output of the antennae to digital sampled received signals; and a processor operative: to receive said digital sampled received signals and to compute at least one real time output parameter comprising a predetermined function of: digitally sampled received signals S, received from the transmitting wireless device at antenna i; and of digitally sampled signals, received from the transmitting wireless device at antenna j and digitally sampled, simultaneously with reception at antenna i and digital sampling of said digitally sampled received signals S, which predetermined function is independent of a power level at which the transmitting device is transmitting, to receive said digital sampled received signals and to compute at least one real time output parameter comprising a predetermined function of: digitally sampled received signals S, received from the transmitting wireless device at antenna i; and of digitally sampled signals, received from the transmitting wireless device at antenna j and digitally sampled, simultaneously with reception at antenna i and digital sampling of said digitally sampled received signals S, digitally sampled received signals S, received from the transmitting wireless device at antenna i; and of digitally sampled signals, received from the transmitting wireless device at antenna j and digitally sampled, simultaneously with reception at antenna i and digital sampling of said digitally sampled received signals S, which predetermined function is independent of a power level at which the transmitting device is transmitting, and to estimate the transmitting wireless device's location within the volume by comparing said at least one real time output parameter to plural reference output parameters respectively having a known correspondence to plural known possible locations within said volume respectively, for at least one pair of antennae i, j from among said N antennae, characterized in that said predetermined function comprises a probability density function of a ratio between: quality of reception of transmission from the transmitting wireless device at antenna i; and simultaneous quality of reception of transmission from the transmitting wireless device at antenna j. quality of reception of transmission from the transmitting wireless device at antenna i; and simultaneous quality of reception of transmission from the transmitting wireless device at antenna j.