A system for retro-transmitting signals, substantially simultaneously towards two or more transmitting sources; wherein the two or more transmitting sources need not be synchronized with the system, and each source transmits a different narrow-band RF signal, the system comprises: two or more antenna elements and two or more respective communication units, each communication unit of each respective antenna element comprises: a receiver configured to receive, via its respective antenna element, a wideband signal signal comprising the different narrow-band RF signals of the two or more transmitting sources; and an analog-to-digital unit configured to sample the received signal; a digital memory unit, a processing unit, a digital-to-analog unit, a transmitting unit; the digital memory unit configured to store samples of the received wideband signal received during a period of time by the respective antenna element, from the two or more transmitting sources, and sampled by the analog-to-digital unit, whereby the samples from each antenna element are stored with an order corresponding to their given sampling order; the processing unit configured and operable for reconstructing a signal including: deciding about at least one sub-group of signal samples that are sampled within said period of time; inverting the sampling orders of said samples of the signal within said at least one sub-group; reconstructing said signal by using said signal samples, which have the inverted sampling order, as data carriers, giving rise to a reconstructed digital signal; so as to reconstruct retro-transmission wideband signals that are transmitted back to said two or more transmitting sources when transmitted synchronously via respective antenna elements; and the digital-to-analog units (1: connected to respective transmitter units of said respective antenna elements and adapted for converting the respective reconstructed digital signals into respective analog transmission signals, substantially simultaneously, such that the analog transmission signals are transmitted in synchronization with one another, thereby enabling said system to retro-transmit the retro-transmission wideband signals towards said two or more transmitting sources simultaneously and thereby enabling coherent receipt of a respective reconstructed signal at each transmitting source. two or more antenna elements and two or more respective communication units, each communication unit of each respective antenna element comprises: a receiver configured to receive, via its respective antenna element, a wideband signal signal comprising the different narrow-band RF signals of the two or more transmitting sources; and an analog-to-digital unit configured to sample the received signal; a digital memory unit, a processing unit, a digital-to-analog unit, a transmitting unit; the digital memory unit configured to store samples of the received wideband signal received during a period of time by the respective antenna element, from the two or more transmitting sources, and sampled by the analog-to-digital unit, whereby the samples from each antenna element are stored with an order corresponding to their given sampling order; the processing unit configured and operable for reconstructing a signal including: deciding about at least one sub-group of signal samples that are sampled within said period of time; inverting the sampling orders of said samples of the signal within said at least one sub-group; reconstructing said signal by using said signal samples, which have the inverted sampling order, as data carriers, giving rise to a reconstructed digital signal; so as to reconstruct retro-transmission wideband signals that are transmitted back to said two or more transmitting sources when transmitted synchronously via respective antenna elements; and the digital-to-analog units (1: connected to respective transmitter units of said respective antenna elements and adapted for converting the respective reconstructed digital signals into respective analog transmission signals, substantially simultaneously, such that the analog transmission signals are transmitted in synchronization with one another, thereby enabling said system to retro-transmit the retro-transmission wideband signals towards said two or more transmitting sources simultaneously and thereby enabling coherent receipt of a respective reconstructed signal at each transmitting source.