| 摘要 |
<p>An apparatus according to one embodiment of the invention includes a transmitter. The transmitter comprises a first gain element configured and arranged to modulate a radio-frequency signal according to a first gain factor to produce a first output signal; and a second gain element configured and arranged to modulate the radio-frequency signal according to a second gain factor to produce a second output signal, wherein a magnitude of the first gain factor varies over time, and wherein a magnitude of the second gain factor varies over time with respect ot the magnitude of the first gain factor. Each of the modulated signals is coupled to a respective antenna. The combined radiation pattern of the antennas varies in an angular direction over time. In a system according to one embodiment of the invention, a base station including such an apparatus receives channel quality indications from mobile units and schedules data transmissions to the mobile units accordingly.</p> |
