US Patent 7620420 Signal transmission apparatus and signal transmission method

A signal transmission apparatus for transmitting a signal using multiple antenna elements comprises a transmission signal generator configured to convert at least one of a first signal addressed to an arbitrary mobile terminal belonging to a geographical area and a second signal addressed to a specific mobile terminal located in a part of the geographical area into one or more transmission signals to be transmitted using a prescribed beam pattern; a weighting adjustor configured to weight said one or more transmission signals for each of the antenna elements to define the prescribed beam pattern; and a signal synthesizer provided for each of the antenna elements and configured to synthesize the weighted transmission signals.