The invention describes a technique for reusing radio frequencies, i.e.,
transmitting two signals on the same frequency at the same time. A signal
is transmitted on one frequency in one pole. A second signal in the same
frequency band is transmitted on one polarity and its inverse is
transmitted on the opposite polarity. By using an antenna that receives
equally both polarities of the second signal and the first signal, the
two inverse signals cancel out, and the second signal can be received and
detected. This signal is suitable for use in mobile applications. By
using an antenna with the feed polarity aligned with the polarity of the
second signal, and only receiving one polarity, the second signal can be
received and detected. This is suited for fixed antenna sites, thus
accomplishing frequency reuse.